i386: Fix some -O0 avx2intrin.h and xopintrin.h intrinsic macros [PR94046]

As the testcases show, the macros we have for -O0 for intrinsics that require
constant argument(s) should first cast the argument to the type the -O1+
inline uses and afterwards to whatever type e.g. a builtin needs.
The PR reported one which violated this, and I've grepped for all double-casts
and grepped out from that meaningful casts where the __m{128,256,512}{,d,i}
first cast is cast to same sized __v* type and has the same kind of element
type (float, double, integral).  These 7 macros were using different casts,
and I've double checked them against the inline function types.

2020-03-05  Jakub Jelinek  <jakub@redhat.com>

	PR target/94046
	* config/i386/avx2intrin.h (_mm_mask_i32gather_ps): Fix first cast of
	SRC and MASK arguments to __m128 from __m128d.
	(_mm256_mask_i32gather_ps): Fix first cast of MASK argument to __m256
	from __m256d.
	(_mm_mask_i64gather_ps): Fix first cast of MASK argument to __m128
	from __m128d.
	* config/i386/xopintrin.h (_mm_permute2_pd): Fix first cast of C
	argument to __m128i from __m128d.
	(_mm256_permute2_pd): Fix first cast of C argument to __m256i from
	__m256d.
	(_mm_permute2_ps): Fix first cast of C argument to __m128i from __m128.
	(_mm256_permute2_ps): Fix first cast of C argument to __m256i from
	__m256.

	* g++.target/i386/pr94046-1.C: New test.
	* g++.target/i386/pr94046-2.C: New test.