x86: Add TARGET_SSE_PARTIAL_REG_[FP_]CONVERTS_DEPENDENCY

x86: Add TARGET_SSE_PARTIAL_REG_[FP_]CONVERTS_DEPENDENCY

1. Replace TARGET_SSE_PARTIAL_REG_DEPENDENCY with
TARGET_SSE_PARTIAL_REG_FP_CONVERTS_DEPENDENCY in SSE FP to FP splitters.
2. Replace TARGET_SSE_PARTIAL_REG_DEPENDENCY with
TARGET_SSE_PARTIAL_REG_CONVERTS_DEPENDENCY in SSE INT to FP splitters.
3.  Also check TARGET_SSE_PARTIAL_REG_FP_CONVERTS_DEPENDENCY and
TARGET_SSE_PARTIAL_REG_DEPENDENCY when handling avx_partial_xmm_update
attribute.  Don't convert AVX partial XMM register update if there is no
partial SSE register dependency for SSE conversion.

gcc/

	* config/i386/i386-features.c (remove_partial_avx_dependency):
	Also check TARGET_SSE_PARTIAL_REG_FP_CONVERTS_DEPENDENCY and
	and TARGET_SSE_PARTIAL_REG_CONVERTS_DEPENDENCY before generating
	vxorps.
	* config/i386/i386.h (TARGET_SSE_PARTIAL_REG_FP_CONVERTS_DEPENDENCY):
	New.
	(TARGET_SSE_PARTIAL_REG_CONVERTS_DEPENDENCY): Likewise.
	* config/i386/i386.md (SSE FP to FP splitters): Replace
	TARGET_SSE_PARTIAL_REG_DEPENDENCY with
	TARGET_SSE_PARTIAL_REG_FP_CONVERTS_DEPENDENCY.
	(SSE INT to FP splitter): Replace TARGET_SSE_PARTIAL_REG_DEPENDENCY
	with TARGET_SSE_PARTIAL_REG_CONVERTS_DEPENDENCY.
	* config/i386/x86-tune.def
	(X86_TUNE_SSE_PARTIAL_REG_FP_CONVERTS_DEPENDENCY): New.
	(X86_TUNE_SSE_PARTIAL_REG_CONVERTS_DEPENDENCY): Likewise.

gcc/testsuite/

	* gcc.target/i386/avx-covert-1.c: New file.
	* gcc.target/i386/avx-fp-covert-1.c: Likewise.
	* gcc.target/i386/avx-int-covert-1.c: Likewise.
	* gcc.target/i386/sse-covert-1.c: Likewise.
	* gcc.target/i386/sse-fp-covert-1.c: Likewise.
	* gcc.target/i386/sse-int-covert-1.c: Likewise.