internal/bytealg: replace use of runtime.support_sse2 with cpu.X86.HasSSE2

This makes the runtime.support_sse2 variable unused
so it is removed in this CL too.

Change-Id: Ia8b9ffee7ac97128179f74ef244b10315e44c234
Reviewed-on: https://go-review.googlesource.com/131455
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/internal/bytealg/compare_386.s

@@ -45,7 +45,7 @@ TEXT cmpbody<>(SB),NOSPLIT,$0-0
 	JEQ	allsame
 	CMPL	BP, $4
 	JB	small
-	CMPB	runtime·support_sse2(SB), $1
+	CMPB	internal∕cpu·X86+const_offsetX86HasSSE2(SB), $1
 	JNE	mediumloop
 largeloop:
 	CMPL	BP, $16

src/runtime/proc.go

@@ -510,7 +510,6 @@ func cpuinit() {
 	// Support cpu feature variables are used in code generated by the compiler
 	// to guard execution of instructions that can not be assumed to be always supported.
 	support_popcnt = cpu.X86.HasPOPCNT
-	support_sse2 = cpu.X86.HasSSE2
 	support_sse41 = cpu.X86.HasSSE41
 
 	arm64_support_atomics = cpu.ARM64.HasATOMICS

src/runtime/runtime2.go

@@ -847,7 +847,6 @@ var (
 	// Set in runtime.cpuinit.
 	// TODO: deprecate these; use internal/cpu directly.
 	support_popcnt        bool
-	support_sse2          bool
 	support_sse41         bool
 	arm64_support_atomics bool