Expose SIMD.Float32x4 type to Javascript.

src/mips/full-codegen-mips.cc

Index: src/mips/full-codegen-mips.cc
diff --git a/src/mips/full-codegen-mips.cc b/src/mips/full-codegen-mips.cc
index 9b36719e324543560668e42339c9b2afbe1754af..6033acd3c04bb71dc3c85028d70aff77ffb01ab1 100644
--- a/src/mips/full-codegen-mips.cc
+++ b/src/mips/full-codegen-mips.cc
@@ -5251,6 +5251,10 @@ 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));