kern: update KernelLdr for 19.0.0 (new checks, dummy function call). ...

Also, fix a few very embarassing mistakes in kernel ldr:
* We have been mapping the page table region RWX for a few years now, accidentally.
* My attempt at making initial page tables not use bit 58 was broken in multiple ways.

kern/ldr: enable the use of relr for relocations

kern: pass kernel base from KernelLdr to Kernel

kern/ldr: move crt0 into .rodata

kern: pass ini1 size from loader to kernel, remove slab memset from init0

mesosphere: remove nostartfiles from specs files (should only be passed to linker wrapper)

kern: refactor init (kill identity map, merge cpu on logic)

kern: increase stack region size when thread resource limit is increased

kern: update for new hw maintenance semantics

ams: support building unit test programs on windows/linux/macos

kern/test: add wip qemu-virt board support to mesosphere

kern: devirtualize most things that are free to devirtualize (see #1672)

kern: put rela in bss ...

NOTE: This saves ~0x4000 of space at the cost of crimes against the linker script.

ams: the copyright^H^H^H^H^H^H^Hmplex plane is the algebraic closure of the reals

kern: update Initialize0 for new arguments/randomization semantics

kern: update initial cache management to match latest kernel

kern: load initial process binary from user pool, rather than from pt heap

kern: swap tpidr_el1/cntv_cval_el0 as scratch vs exception stack

kern: update KInitialPageTable/KInitialPageAllocator

kern: remove target-firmware logic for kernel loader

kern: implement thread call stack debug

kern: update Initialize0 to account for new ordering

kldr: update for 11.0.0

Meso build targets (#1196) ...

* meso: commit wip (thanks fincs) rewrite to support build targets

* meso: commit mostly-working build system

* meso: correct .o dependencies in kernel/kldr

* libstratosphere: fix building after PCH related build changes

Co-authored-by: fincs <fincs@devkitpro.org>

kern: improve resource region size definitions/calculations

kern: make GetTargetFirmware a compile-time constant when not building for Switch

kern: fix multicore instruction cache invalidation

kern: fix built-in usage for libc

ams: update build system to add generic-fallback support

kernel_ldr: use unoptimized memcpy before mmu bringup (closes #1102) ...

Before the MMU is up, all reads/writes must be aligned; the optimized
memcpy implementation does not guarantee all reads/writes it performs
are aligned.

This commit splits the libc impl to be separate for kernel/kernel_ldr,
and so now only kernel will use the optimized impl. This is safe,
as the MMU is brought up before kernel begins executing.