Expose SIMD.Float32x4 type to Javascript.

src/mips/lithium-codegen-mips.cc

Index: src/mips/lithium-codegen-mips.cc
diff --git a/src/mips/lithium-codegen-mips.cc b/src/mips/lithium-codegen-mips.cc
index b1166c7c647bbc10c5f7897c43e0df668e281d3a..8c70c2184bf6fab0968e1453cbe3a8cfc6fc4bd8 100644
--- a/src/mips/lithium-codegen-mips.cc
+++ b/src/mips/lithium-codegen-mips.cc
@@ -2181,6 +2181,14 @@ void LCodeGen::DoBranch(LBranch* instr) {
         __ Branch(instr->TrueLabel(chunk_), eq, scratch, Operand(SYMBOL_TYPE));
       }
 
+      if (expected.Contains(ToBooleanStub::SIMD_VALUE)) {
+        // SIMD value -> true.
+        const Register scratch = scratch1();
+        __ lbu(scratch, FieldMemOperand(map, Map::kInstanceTypeOffset));
+        __ Branch(instr->TrueLabel(chunk_), eq, scratch,
+                  Operand(FLOAT32X4_TYPE));
+      }
+
       if (expected.Contains(ToBooleanStub::HEAP_NUMBER)) {
         // heap number -> false iff +0, -0, or NaN.
         DoubleRegister dbl_scratch = double_scratch0();
@@ -5718,6 +5726,13 @@ Condition LCodeGen::EmitTypeofIs(Label* true_label,
     *cmp2 = Operand(zero_reg);
     final_branch_condition = eq;
 
+  } else if (String::Equals(type_name, factory->float32x4_string())) {
+    __ JumpIfSmi(input, false_label);
+    __ GetObjectType(input, input, scratch);
+    *cmp1 = scratch;
+    *cmp2 = Operand(FLOAT32X4_TYPE);
+    final_branch_condition = eq;
+
   } else {
     *cmp1 = at;
     *cmp2 = Operand(zero_reg);  // Set to valid regs, to avoid caller assertion.