Allow building AVX2 on x86 (suggestion by @samuel-lee-msft)

[msprotz]

No description provided.

[msprotz]

So I'm confused. Here's the problematic compiler invocation:

/usr/bin/clang -DCMAKE_INTDIR=\"Debug\" -I/home/runner/work/hacl-packages/hacl-packages/include -I/home/runner/work/hacl-packages/hacl-packages/build -I/home/runner/work/hacl-packages/hacl-packages/karamel/include -I/home/runner/work/hacl-packages/hacl-packages/karamel/krmllib/dist/minimal -I/home/runner/work/hacl-packages/hacl-packages/vale/include -I/home/runner/work/hacl-packages/hacl-packages/libcrux/include -I/home/runner/work/hacl-packages/hacl-packages/libcrux/eurydice -m32 -g -std=gnu11 -g -Og -fPIC -fsanitize=address -fno-omit-frame-pointer -fsanitize=undefined -DHACL_CAN_COMPILE_VEC128 -msse2 -msse3 -msse4.1 -msse4.2 -MD -MT CMakeFiles/hacl_vec128.dir/Debug/src/Hacl_MAC_Poly1305_Simd128.c.o -MF CMakeFiles/hacl_vec128.dir/Debug/src/Hacl_MAC_Poly1305_Simd128.c.o.d -o CMakeFiles/hacl_vec128.dir/Debug/src/Hacl_MAC_Poly1305_Simd128.c.o -c /home/runner/work/hacl-packages/hacl-packages/src/Hacl_MAC_Poly1305_Simd128.c
/home/runner/work/hacl-packages/hacl-packages/src/Hacl_MAC_Poly1305_Simd128.c:78:40: warning: implicit declaration of function '_mm_insert_epi64' is invalid in C99 [-Wimplicit-function-declaration]
  Lib_IntVector_Intrinsics_vec128 f0 = Lib_IntVector_Intrinsics_vec128_insert64(acc0, 0ULL, 1U);

The error is about _mm_insert_epi64 not being defined. But according to https://www.intel.com/content/www/us/en/docs/intrinsics-guide/index.html#text=_mm_insert_epi64&ig_expand=3835 :

• this should be found in #include <smmintrin.h> which we do have in libintvector.h
• this is predicated on having sse4.1 which is ok since we do pass -msse4.1 to the compiler

@franziskuskiefer any clue?

(I am hearing that specific change works on Windows.)

[coveralls]

Pull Request Test Coverage Report for Build 9150790138

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 59.064%

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Totals
Change from base Build 9096505835:	0.0%
Covered Lines:	38622
Relevant Lines:	65390

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💛 - Coveralls