Only initialize mutexes during DllMain #2747

Job	Run time
chromium	1m 20s
linux (gcc, g++, Debug, ubuntu-20.04)	2m 55s
codegen	11s
linux (gcc, g++, Debug, ubuntu-22.04)	2m 55s
iOS	54s
linux-32 (Debug)	1m 39s
tvOS	45s
linux-32-no-asm	2m 6s
linux-32 (Release)	2m 11s
linux (gcc, g++, Release, ubuntu-20.04)	6m 33s
linux-no-asm	3m 18s
linux (gcc, g++, Release, ubuntu-22.04)	6m 58s
mac (Debug, APPLE_STATIC_LOADER=ON)	4m 1s
Universal Binary Testing (STATIC ON) w/ Ninja	1m 43s
linux (clang, clang++, Debug, ubuntu-20.04)	2m 7s
mac (Debug, APPLE_STATIC_LOADER=OFF)	5m 45s
Universal Binary Testing (STATIC ON) w/ Xcode	4m 55s
mingw	1m 56s
linux (clang, clang++, Debug, ubuntu-22.04)	3m 9s
mac (Release, APPLE_STATIC_LOADER=ON)	5m 51s
Universal Binary Testing (STATIC OFF) w/ Ninja	1m 43s
linux (clang, clang++, Release, ubuntu-20.04)	4m 29s
mac (Release, APPLE_STATIC_LOADER=OFF)	5m 5s
Universal Binary Testing (STATIC OFF) w/ Xcode	5m 17s
linux (clang, clang++, Release, ubuntu-22.04)	4m 50s
mingw-no-asm	1m 12s
mingw-use-gas	1m 20s
mingw-no-asm-explicit	55s
windows_clang (clang, Debug)	3m 15s
windows_vs (Win32, Debug)	3m 36s
windows_clang (clang, Release)	3m 2s
windows_vs-no-asm (Win32)	4m 44s
windows_vs (Win32, Release)	4m 50s
windows_clang (clang-cl, Debug)	3m 43s
windows_vs-no-asm (x64)	4m 33s
windows_vs (x64, Debug)	4m 8s
windows_clang (clang-cl, Release)	3m 14s
windows_vs (x64, Release)	4m 10s
	2h 5m 18s

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