ams: avoid UB infinite loops

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.

kern: complete final SVC stubs (KernelDebug/Trace debug-impl still TODO)

kern: SvcReturnFromException

kern: fix dynamic calculation of slab heap size

kern SvcGetDebugThreadContext, SvcSetDebugThreadContext

kern: SvcGetDebugThreadParam

kern: clean up majority of TODOs

kern: resolve final non-user-exception MESOSPHERE_UNIMPLEMENTED

kern: SvcGetDebugEventInfo64From32

kern: resolve MESOSPHERE_UNIMPLEMENTEDs other than UserException

kern: Add real SvcBreak implementation

kern: SvcBreakDebugProcess, SvcTerminateDebugProcess

kern: SvcSetHardwareBreakPoint

kern: Svc(Legacy)ContinueDebugEvent

kern: Add 4.x InitialProcessIdRange to SvcGetInfo

kern: SvcQueryPhysicalAddress

kern: style parity for return in GetThreadList

kern: SvcGetThreadList

kern: SvcGetLastThreadInfo, SvcGetDebugFutureThreadInfo

kern: SvcFlushDataCache, SvcFlushEntireDataCache

kern: SvcReadDebugProcessMemory, SvcWriteDebugProcessMemory

kern: automatic PC alignment on ERET is implementation defined

kern: switch memset to optimized impl

kern: use optimized memcmp/memcpy implementations

SvcQueryDebugProcessMemory

kern: fix ARM vs THUMB mode selection on 32-bit entry

kern: fix whoops in light ipc

kern: SendSyncRequestLight, ReplyAndReceiveLight

kern: fix bug in server handle cleanup