Inline Math.fround in optimized code.

src/arm64/lithium-arm64.cc

Index: src/arm64/lithium-arm64.cc
diff --git a/src/arm64/lithium-arm64.cc b/src/arm64/lithium-arm64.cc
index f7ac46faaf6f6e988fb22bb446e174806a775a17..ff224182601d97c4d883f286411a27e26aafe770 100644
--- a/src/arm64/lithium-arm64.cc
+++ b/src/arm64/lithium-arm64.cc
@@ -2648,6 +2648,12 @@ LInstruction* LChunkBuilder::DoUnaryMathOperation(HUnaryMathOperation* instr) {
         return DefineAsRegister(result);
       }
     }
+    case kMathFround: {
+      ASSERT(instr->value()->representation().IsDouble());
+      LOperand* input = UseRegister(instr->value());
+      LMathFround* result = new (zone()) LMathFround(input);
+      return DefineAsRegister(result);
+    }
     case kMathSqrt: {
       ASSERT(instr->representation().IsDouble());
       ASSERT(instr->value()->representation().IsDouble());