headers: Mark RtlUnwind* functions as noreturn #33

Job	Run time
llvm-mingw (ucrt)	9m 41s
gcc (msvcrt, i686)	19m 25s
llvm-mingw (msvcrt)	10m 6s
gcc (msvcrt, x86_64)	19m 48s
gcc (ucrt, x86_64)	20m 17s
gcc (ucrt, i686)	19m 10s
llvm-mingw (ucrtbase)	9m 50s
test-llvm-mingw	0s
test-libcxx	0s
linux-test-cross-build-ffmpeg	0s
test-ffmpeg	0s
gcc-cross (ucrt, x86_64)	17m 29s
gcc-cross (ucrt, i686)	16m 46s
gcc-cross (msvcrt, i686)	17m 8s
gcc-cross (msvcrt, x86_64)	18m 24s
test-gcc (ucrt, i686)	45s
test-gcc (ucrt, x86_64)	47s
test-gcc (msvcrt, x86_64)	41s
test-gcc (msvcrt, i686)	44s
	3h 1m 1s

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