s390: Remove usages of Heap::NewSpaceStart and its external reference

src/crankshaft/s390/lithium-s390.cc

Index: src/crankshaft/s390/lithium-s390.cc
diff --git a/src/crankshaft/s390/lithium-s390.cc b/src/crankshaft/s390/lithium-s390.cc
index 8d0481f2a60fa4a58785096ec0ae5e987a439c9a..ff577a6df0fe1da22a6deaf070071d41c1d72eb5 100644
--- a/src/crankshaft/s390/lithium-s390.cc
+++ b/src/crankshaft/s390/lithium-s390.cc
@@ -2063,9 +2063,10 @@ LInstruction* LChunkBuilder::DoTransitionElementsKind(
 LInstruction* LChunkBuilder::DoTrapAllocationMemento(
     HTrapAllocationMemento* instr) {
   LOperand* object = UseRegister(instr->object());
-  LOperand* temp = TempRegister();
+  LOperand* temp1 = TempRegister();
+  LOperand* temp2 = TempRegister();
   LTrapAllocationMemento* result =
-      new (zone()) LTrapAllocationMemento(object, temp);
+      new (zone()) LTrapAllocationMemento(object, temp1, temp2);
   return AssignEnvironment(result);
 }