Expose SIMD.Float32x4 type to Javascript.

src/x87/full-codegen-x87.cc

Index: src/x87/full-codegen-x87.cc
diff --git a/src/x87/full-codegen-x87.cc b/src/x87/full-codegen-x87.cc
index 8b84d9404fb8875264862f64e98f2714c77ea152..ef8d5d993449db107145e58d2e86f2e00ca8a260 100644
--- a/src/x87/full-codegen-x87.cc
+++ b/src/x87/full-codegen-x87.cc
@@ -5152,6 +5152,10 @@ void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
     __ JumpIfSmi(eax, if_false);
     __ CmpObjectType(eax, SYMBOL_TYPE, edx);
     Split(equal, if_true, if_false, fall_through);
+  } else if (String::Equals(check, factory->float32x4_string())) {
+    __ JumpIfSmi(eax, if_false);
+    __ CmpObjectType(eax, FLOAT32X4_TYPE, edx);
+    Split(equal, if_true, if_false, fall_through);
   } else if (String::Equals(check, factory->boolean_string())) {
     __ cmp(eax, isolate()->factory()->true_value());
     __ j(equal, if_true);