MIPS64: Fix allocation folding test failures.

src/crankshaft/mips64/lithium-mips64.cc

Index: src/crankshaft/mips64/lithium-mips64.cc
diff --git a/src/crankshaft/mips64/lithium-mips64.cc b/src/crankshaft/mips64/lithium-mips64.cc
index 53baa8d1979b2c3a81e1d9accf25ebabe685746e..4bcd720f4093c7ede746b4146dbd565ce86f46de 100644
--- a/src/crankshaft/mips64/lithium-mips64.cc
+++ b/src/crankshaft/mips64/lithium-mips64.cc
@@ -2303,13 +2303,18 @@ LInstruction* LChunkBuilder::DoStringCharFromCode(HStringCharFromCode* instr) {
 
 
 LInstruction* LChunkBuilder::DoAllocate(HAllocate* instr) {
-  info()->MarkAsDeferredCalling();
-  LOperand* context = UseAny(instr->context());
   LOperand* size = UseRegisterOrConstant(instr->size());
   LOperand* temp1 = TempRegister();
   LOperand* temp2 = TempRegister();
-  LAllocate* result = new(zone()) LAllocate(context, size, temp1, temp2);
-  return AssignPointerMap(DefineAsRegister(result));
+  if (instr->IsAllocationFolded()) {
+    LFastAllocate* result = new (zone()) LFastAllocate(size, temp1, temp2);
+    return DefineAsRegister(result);
+  } else {
+    info()->MarkAsDeferredCalling();
+    LOperand* context = UseAny(instr->context());
+    LAllocate* result = new (zone()) LAllocate(context, size, temp1, temp2);
+    return AssignPointerMap(DefineAsRegister(result));
+  }
 }