i386: Prevent spurious FP exceptions with _mm_cvt{,t}ps_pi32 [PR98522]

i386: Prevent spurious FP exceptions with _mm_cvt{,t}ps_pi32 [PR98522]

Prevent spurious FP exceptions with _mm_cvt{,t}ps_pi32 for TARGET_MMX_WITH_SSE
by clearing the top 64 bytes of the input XMM register.

2021-01-05  Uroš Bizjak  <ubizjak@gmail.com>

gcc/
	PR target/98522
	* config/i386/sse.md (sse_cvtps2pi): Redefine as define_insn_and_split.
	Clear the top 64 bytes of the input XMM register.
	(sse_cvttps2pi): Ditto.

gcc/testsuite

	PR target/98522
	* gcc.target/i386/pr98522.c: New test.