Remove check for SAHF support in ia32.

On ia32, SAHF is guaranteed. It's only necessary to probe for it on x64.

R=svenpanne@chromium.org
BUG=376087
LOG=N

Review URL: https://codereview.chromium.org/296133006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21422 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/ia32/assembler-ia32.cc

@@ -52,8 +52,6 @@ void CpuFeatures::ProbeImpl(bool cross_compile) {
   CPU cpu;
   CHECK(cpu.has_sse2());  // SSE2 support is mandatory.
   CHECK(cpu.has_cmov());  // CMOV support is mandatory.
-  CHECK(cpu.has_sahf());  // SAHF must be available in compat/legacy mode.
-  supported_ |= 1u << SAHF;
   supported_ |= OS::CpuFeaturesImpliedByPlatform();
 
   // Only use statically determined features for cross compile (snapshot).