Expose SIMD.Float32x4 type to Javascript.

src/mips64/full-codegen-mips64.cc

Index: src/mips64/full-codegen-mips64.cc
diff --git a/src/mips64/full-codegen-mips64.cc b/src/mips64/full-codegen-mips64.cc
index 1102b9e28c98fa9936b6f7b0389d0810a5e5f1b1..cb5992ca36e95497c85191d2917cbf1d8d3bf532 100644
--- a/src/mips64/full-codegen-mips64.cc
+++ b/src/mips64/full-codegen-mips64.cc
@@ -5252,6 +5252,10 @@ void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
     __ JumpIfSmi(v0, if_false);
     __ GetObjectType(v0, v0, a1);
     Split(eq, a1, Operand(SYMBOL_TYPE), if_true, if_false, fall_through);
+  } else if (String::Equals(check, factory->float32x4_string())) {
+    __ JumpIfSmi(v0, if_false);
+    __ GetObjectType(v0, v0, a1);
+    Split(eq, a1, Operand(FLOAT32X4_TYPE), if_true, if_false, fall_through);
   } else if (String::Equals(check, factory->boolean_string())) {
     __ LoadRoot(at, Heap::kTrueValueRootIndex);
     __ Branch(if_true, eq, v0, Operand(at));