arm64: fix clang ICE on Windows for thunderx2t kernels

[vtjnash]

Guard .align directive to avoid internal compiler error on AArch64 Windows with clang.

See: llvm/llvm-project#149547
Update of #5566 to fix remaining issues
See: #5076

[martin-frbg]

I believe the _MSC_VER to be equivalent here (it will never match plain MSVC as that can't handle the inline assembly anyway, but it matches any LLVM derivative that uses the clang-cl shim) ?

[vtjnash]

It might be similar? Hard to check exactly if all libc specify that clang+_WIN32 is exactly the same as MSC when this needs to do is to specify clang+_WIN32 and exclude MSVC. It is just very confusing to intentionally use a macro to work around a bug in one specific compiler by specifying that this should be disabled for a completely different compiler

[martin-frbg]

Thanks - did you happen to check if these changes are sufficient for using these files with WoA ? I think it is likely that they might need changes to the storing of the complex results (similar to the earlier zdot changes) but I won't get around to checking this myself today

[vtjnash]

Thanks - did you happen to check if these changes are sufficient for using these files with WoA ?

I'm not precisely sure what you want checked. It compiles and seems to pass tests. clang has always supported c99 just fine (unlike MSVC, which still is buggy):

OpenBLAS/common.h

Lines 579 to 583 in 5ffbf38

	/* C99 supports complex floating numbers natively, which GCC also offers as an
	extension since version 3.0. If neither are available, use a compatible
	structure as fallback (see Clause 6.2.5.13 of the C99 standard). */
	#if ((defined(__STDC_IEC_559_COMPLEX__) || __STDC_VERSION__ >= 199901L || \
	(__GNUC__ >= 3 && !defined(__cplusplus))) && !(defined(FORCE_OPENBLAS_COMPLEX_STRUCT))) && !defined(_MSC_VER)