Inline Math.fround in optimized code.

src/arm64/lithium-codegen-arm64.cc

Index: src/arm64/lithium-codegen-arm64.cc
diff --git a/src/arm64/lithium-codegen-arm64.cc b/src/arm64/lithium-codegen-arm64.cc
index 4725b98a508240855116ce5ad81ddf98d76c1e2d..aa6030e3026e574613fb341d93132f4e46e35cb4 100644
--- a/src/arm64/lithium-codegen-arm64.cc
+++ b/src/arm64/lithium-codegen-arm64.cc
@@ -4200,6 +4200,14 @@ void LCodeGen::DoMathRoundI(LMathRoundI* instr) {
 }
 
 
+void LCodeGen::DoMathFround(LMathFround* instr) {
+  DoubleRegister input = ToDoubleRegister(instr->value());
+  DoubleRegister result = ToDoubleRegister(instr->result());
+  __ Fcvt(result.S(), input);
+  __ Fcvt(result, result.S());
+}
+
+
 void LCodeGen::DoMathSqrt(LMathSqrt* instr) {
   DoubleRegister input = ToDoubleRegister(instr->value());
   DoubleRegister result = ToDoubleRegister(instr->result());