ARM64: Small optimisations

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 6bd7c5b584bd73a923debde6edf704b5b9bf88c8..d18808a587b1cd2a50dc9a58120786de46a978ea 100644
--- a/src/arm64/lithium-arm64.cc
+++ b/src/arm64/lithium-arm64.cc
@@ -2009,10 +2009,9 @@ LInstruction* LChunkBuilder::DoDoubleBits(HDoubleBits* instr) {
 
 
 LInstruction* LChunkBuilder::DoConstructDouble(HConstructDouble* instr) {
-  LOperand* lo = UseRegister(instr->lo());
+  LOperand* lo = UseRegisterAndClobber(instr->lo());
   LOperand* hi = UseRegister(instr->hi());
-  LOperand* temp = TempRegister();
-  return DefineAsRegister(new(zone()) LConstructDouble(hi, lo, temp));
+  return DefineAsRegister(new(zone()) LConstructDouble(hi, lo));
 }