Inline Math.fround in optimized code.

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index 188f5a7fb8a5bf94b7122c29745f958f3ead7133..92ef3aa316ee729d453d41cffb113561a92fd2f6 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -3848,6 +3848,15 @@ void LCodeGen::DoMathRound(LMathRound* instr) {
 }
 
 
+void LCodeGen::DoMathFround(LMathFround* instr) {
+  DwVfpRegister input_reg = ToDoubleRegister(instr->value());
+  DwVfpRegister output_reg = ToDoubleRegister(instr->result());
+  LowDwVfpRegister scratch = double_scratch0();
+  __ vcvt_f32_f64(scratch.low(), input_reg);
+  __ vcvt_f64_f32(output_reg, scratch.low());
+}
+
+
 void LCodeGen::DoMathSqrt(LMathSqrt* instr) {
   DwVfpRegister input = ToDoubleRegister(instr->value());
   DwVfpRegister result = ToDoubleRegister(instr->result());