Allow tests to directly call loader internal functions & Always memset newly reallocated memory #2908

Job	Run time
codegen	13s
linux-no-asm	3m 30s
linux (gcc, g++, Debug, ubuntu-20.04)	2m 50s
linux-32 (Debug)	2m 27s
linux (gcc, g++, Debug, ubuntu-22.04)	3m 30s
chromium	1m 24s
linux-32-no-asm	2m 12s
linux-32 (Release)	2m 11s
linux (gcc, g++, Release, ubuntu-20.04)	6m 59s
linux (gcc, g++, Release, ubuntu-22.04)	6m 58s
linux (clang, clang++, Debug, ubuntu-20.04)	2m 13s
linux (clang, clang++, Debug, ubuntu-22.04)	3m 24s
linux (clang, clang++, Release, ubuntu-20.04)	4m 28s
linux (clang, clang++, Release, ubuntu-22.04)	5m 4s
windows_vs (Win32, Debug)	5m 16s
windows_vs (Win32, Release)	4m 58s
mingw-no-asm-explicit	1m 17s
windows_vs (x64, Debug)	4m 57s
mingw	1m 59s
mingw-no-asm	1m 2s
windows_vs (x64, Release)	4m 34s
windows_clang (clang, Debug)	4m 0s
mingw-use-gas	1m 8s
windows_vs-no-asm (Win32)	4m 35s
windows_clang (clang, Release)	3m 31s
windows_clang (clang-cl, Debug)	3m 49s
windows_vs-no-asm (x64)	4m 15s
windows_clang (clang-cl, Release)	3m 58s
iOS	49s
Universal Binary Testing (STATIC ON) w/ Ninja	2m 40s
tvOS	44s
mac (Debug, APPLE_STATIC_LOADER=ON)	3m 16s
Universal Binary Testing (STATIC ON) w/ Xcode	3m 41s
mac (Debug, APPLE_STATIC_LOADER=OFF)	4m 24s
mac (Release, APPLE_STATIC_LOADER=ON)	4m 11s
Universal Binary Testing (STATIC OFF) w/ Ninja	2m 19s
mac (Release, APPLE_STATIC_LOADER=OFF)	5m 35s
Universal Binary Testing (STATIC OFF) w/ Xcode	2m 23s
	2h 6m 44s

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