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

src/crankshaft/ppc/lithium-ppc.h

Index: src/crankshaft/ppc/lithium-ppc.h
diff --git a/src/crankshaft/ppc/lithium-ppc.h b/src/crankshaft/ppc/lithium-ppc.h
index 9245f849f627d1b65375ddcd5262eafd4a85f450..c39f6204f81251f72d1727e4db7319c83409743d 100644
--- a/src/crankshaft/ppc/lithium-ppc.h
+++ b/src/crankshaft/ppc/lithium-ppc.h
@@ -2058,16 +2058,17 @@ class LTransitionElementsKind final : public LTemplateInstruction<0, 2, 1> {
   ElementsKind to_kind() { return hydrogen()->to_kind(); }
 };
 
-
-class LTrapAllocationMemento final : public LTemplateInstruction<0, 1, 1> {
+class LTrapAllocationMemento final : public LTemplateInstruction<0, 1, 2> {
  public:
-  LTrapAllocationMemento(LOperand* object, LOperand* temp) {
+  LTrapAllocationMemento(LOperand* object, LOperand* temp1, LOperand* temp2) {
     inputs_[0] = object;
-    temps_[0] = temp;
+    temps_[0] = temp1;
+    temps_[1] = temp2;
   }
 
   LOperand* object() { return inputs_[0]; }
-  LOperand* temp() { return temps_[0]; }
+  LOperand* temp1() { return temps_[0]; }
+  LOperand* temp2() { return temps_[1]; }
 
   DECLARE_CONCRETE_INSTRUCTION(TrapAllocationMemento, "trap-allocation-memento")
 };