This implements two optimizations on fs::Path, which N added in 12.0.0.

The current structure looks like: 

```cpp
struct Path {
    const char *m_str; // Points to the read-only path string
    char *m_write_buffer_buffer; // Part of std::unique_ptr<char[], ams::fs::impl::Deleter>
    ams::fs::impl::Deleter m_write_buffer_deleter; // Parse of std::unique_ptr<char[], ams::fs::impl::Deleter>, stores the size of the buffer.
    size_t m_write_buffer_length; // Copy of the write buffer's size accessible to the Path() structure.
    bool m_is_normalized; // Whether the path buffer is normalized
};
```

This is pretty wasteful. The write buffer size is stored twice, wasting 8 bytes, because one copy of the size isn't accessible to the path.

In addition, due to alignment, the bool wastes 7 padding bytes.

This commit:

* Encodes normalized in the low bit of the write buffer length, saving 8 bytes.
* Use a custom WriteBuffer class rather than generic unique_ptr, to avoid needing to store the WriteBuffer twice.


These each save 8 bytes, for a final size of 0x18 rather than 0x28.

* fs: implement support for interacting with ncas.

* spl: extend to use virtual keyslots

* ams: update to build with gcc10/c++20

* remove mno-outline-atomics

* ams: take care of most TODO C++20s

* fusee/sept: update for gcc10

* whoosh, your code now uses pre-compiled headers

* make: dependency fixes

* Implement NCM

* Modernize ncm_main

* Remove unnecessary smExit

* Give access to svcCallSecureMonitor

* Stack size bump

* Fix incorrect setup for NandUser's content storage entry

* Fix a potential data abort when flushing the placeholder accessor cache

* Fix HasFile and HasDirectory

* Use r+b, not w+b

* Misc fixes

* errno begone

* Fixed more stdio error handling

* More main fixes

* Various command improvements

* Make dispatch tables great again

* Fix logic inversion

* Fixed content path generation

* Bump heap size, fix CleanupAllPlaceHolder

* Various fixes. Note: This contains debug stuff which will be removed later. I was getting tired of having to cherrypick tiny changes

* Fixed placeholder/content deletion

* Fixed incorrect content manager destruction

* Prevent automatic placeholder creation on open

* Fixed List implementation. Also lots of debug logging.

* Removed debug code

* Added a scope guard for WritePlaceHolder

* Manually prevent placeholder/content appending

* Revert "Removed debug code"

This reverts commit d6ff261.

* Always cache placeholder file. Switch to ftell for preventing appending

* Universally use EnsureEnabled

* Abstract away file writing logic

* Misc cleanup

* Refactor placeholder cacheing

* Remove debug code (again)

* Revert "Remove debug code (again)"

This reverts commit 168447d.

* Misc changes

* Fixed file modes

* Fixed ContentId/PlaceHolderId alignment

* Improved type safety

* Fixed reinitialization

* Fixed doubleup on path creation

* Remove debug code

* Fixed 1.0.0 booting

* Correct amount of add on content

* Correct main thread stack size

* lr: Introducing registered data

* Reorder stratosphere Makefile

* Move results to libstrat

* lr: Cleanup lr_redirection

* lr: lr_manager tweaks

* lr: Imrpoved path handling and adjust ResolveAddOnContentPath order

* lr: Organise types

* Add eof newlines

* lr: Eliminate unnecessary vars

* lr: Unnecessary vars 2 electric boogaloo

* lr: Various helpers

* lr: RegisteredLocationResolver helpers

* ncm: Move ncm_types to libstrat

* ncm: Misc cleanup

* Implement NCM

* Modernize ncm_main

* Remove unnecessary smExit

* Give access to svcCallSecureMonitor

* Stack size bump

* Fix incorrect setup for NandUser's content storage entry

* Fix a potential data abort when flushing the placeholder accessor cache

* Fix HasFile and HasDirectory

* Use r+b, not w+b

* Misc fixes

* errno begone

* Fixed more stdio error handling

* More main fixes

* Various command improvements

* Make dispatch tables great again

* Fix logic inversion

* Fixed content path generation

* Bump heap size, fix CleanupAllPlaceHolder

* Various fixes. Note: This contains debug stuff which will be removed later. I was getting tired of having to cherrypick tiny changes

* Fixed placeholder/content deletion

* Fixed incorrect content manager destruction

* Prevent automatic placeholder creation on open

* Fixed List implementation. Also lots of debug logging.

* Removed debug code

* Added a scope guard for WritePlaceHolder

* Manually prevent placeholder/content appending

* Revert "Removed debug code"

This reverts commit d6ff261.

* Always cache placeholder file. Switch to ftell for preventing appending

* Universally use EnsureEnabled

* Abstract away file writing logic

* Misc cleanup

* Refactor placeholder cacheing

* Remove debug code (again)

* Revert "Remove debug code (again)"

This reverts commit 168447d.

* Misc changes

* Fixed file modes

* Fixed ContentId/PlaceHolderId alignment

* Improved type safety

* Fixed reinitialization

* Fixed doubleup on path creation

* Remove debug code

* Fixed 1.0.0 booting

* Correct amount of add on content

* Correct main thread stack size

* lr: Introducing registered data

* Reorder stratosphere Makefile

* Move results to libstrat

* lr: Cleanup lr_redirection

* lr: lr_manager tweaks

* lr: Imrpoved path handling and adjust ResolveAddOnContentPath order

* lr: Organise types

* Add eof newlines

* lr: Eliminate unnecessary vars

* lr: Unnecessary vars 2 electric boogaloo

* lr: Various helpers

* lr: RegisteredLocationResolver helpers

* ncm: Move ncm_types to libstrat

* ncm: Misc cleanup

* Updated AddOnContentLocationResolver and RegisteredLocationResolver to 9.0.0

* Finished updating lr to 9.0.0

* Updated NCM to 9.0.0

* Fix libstrat includes

* Fixed application launching

* title_id_2 -> owner_tid

* Updated to new-ipc

* Change to using pure virtuals

* Title Id -> Program Id

* Fixed compilation against master

* std::scoped_lock<> -> std::scoped_lock

* Adopted R_UNLESS and R_CONVERT

* Prefix namespace to Results

* Adopt std::numeric_limits

* Fixed incorrect error handling in ReadFile

* Adopted AMS_ABORT_UNLESS

* Adopt util::GenerateUuid()

* Syntax improvements

* ncm_types: Address review

* Address more review comments

* Updated copyrights

* Address more feedback

* More feedback addressed

* More changes

* Move dispatch tables out of interface files

* Addressed remaining comments

* lr: move into libstratosphere

* ncm: Fix logic inversion

* lr: Add comments

* lr: Remove whitespace

* ncm: Start addressing feedback

* ncm: Cleanup InitializeContentManager

* lr: support client-side usage

* lr_service -> lr_api

* ncm: Begin refactoring content manager

* ncm: More content manager improvements

* ncm: Content manager mount improvements

* ldr: use lr bindings

* lr bindings usage: minor fixes

* ncm/lr: Pointer placement

* ncm: placeholder accessor cleanup

* ncm: minor fixes

* ncm: refactor rights cache

* ncm: content meta database cleanup

* ncm: move content meta database impl out of interface file

* ncm: Use const ContentMetaKey &

* ncm: fix other non-const ContentMetaKey references

* ncm: content meta database cleanup

* ncm: content storage fixes for 2.0.0

* ncm: add missing end of file newlines

* ncm: implement ContentMetaReader

* ncm: client-side api

* ncm: trim trailing spaces

* ncm: FS_MAX_PATH-1 -> fs::EntryNameLengthMax

* ncm: Use PathString and Path

* fs: implement accessor wrappers for ncm

* fs: implement user fs wrappers

* fs: add MountSdCard

* ncm: move to content manager impl

* ncm: fix up main

* kvdb: use fs::

* fs: Add wrappers needed for ncm

* ncm: use fs bindings, other refactoring

* ncm: minor fixes

* fsa: fix ReadFile without size output

* fs: add substorage, rom path tool

* ncm: fix dangling fsdev usage

* fs: fix bug in Commit

* fs: fixed incorrect mode check

* fs: implement Mount(System)Data

* ncm: don't delete hos

* results: add R_SUCCEED_IF

* ams-except-ncm: use R_SUCCEED_IF

* ncm: added comments

* ncm: fix api definitions

* ncm: use R_SUCCEED_IF

* pm: think of the savings

* ncm: employ kernel strats

* ncm: Nintendo has 5 MiB of heap. Give ourselves 4 to be safe, pending analysis

* ncm: refactor IDs, split types header into many headers

* ams.mitm: use fs bindings instead of stdio

* fs: SystemData uses SystemDataId

* ncm: improve meta-db accuracy

* ncm: inline getlatestkey

* fs: improve UnsupportedOperation results

* fs: modernize mount utils

* ams: misc fixes for merge-errors

* fs: improve unsupportedoperation results

* git subrepo pull emummc

subrepo:
  subdir:   "emummc"
  merged:   "d12dd546"
upstream:
  origin:   "https://github.com/m4xw/emuMMC"
  branch:   "develop"
  commit:   "d12dd546"
git-subrepo:
  version:  "0.4.1"
  origin:   "???"
  commit:   "???"

* util: add boundedmap

* ncm: minor style fixes

* ncm: don't unmount if mounting fails

* lr: bug fixes

* ncm: implement ncm.for-initialize + ncm.for-safemode

* lr: ncm::ProgramId::Invalid -> ncm::InvalidProgramId

* ncm: fix open directory mode on 1.0.0

* ncm: fix fs use, implement more of < 4.0.0 for-initialize/safemode

* ncm: implement packagedcontent -> content for building metadb

* ncm: fix save data flag management

* ncm: address some review suggestions (thanks @leoetlino!)

* updater: use fs bindings

* fs: implement MountCode

* fs: prefer make_unique to operator new

* ncm: implement remaining ContentMetaDatabaseBuilder functionality

Co-authored-by: Michael Scire <SciresM@gmail.com>