[turbofan] Properly emit vsqrtsd if AVX is enabled.

We shall not mix AVX and SSE instructions as that can cause performance
regressions in some areas, so make sure to emit vsqrtsd instead of
sqrtsd when AVX is enabled.

R=ahaas@chromium.org

Review-Url: https://codereview.chromium.org/2335603002
Cr-Commit-Position: refs/heads/master@{#39349}

src/compiler/x64/code-generator-x64.cc

@@ -1454,7 +1454,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       break;
     }
     case kSSEFloat64Sqrt:
-      ASSEMBLE_SSE_UNOP(sqrtsd);
+      ASSEMBLE_SSE_UNOP(Sqrtsd);
       break;
     case kSSEFloat64Round: {
       CpuFeatureScope sse_scope(masm(), SSE4_1);