Use compilation info isolate pointer in lithium codegen.

src/arm/lithium-codegen-arm.h

Index: src/arm/lithium-codegen-arm.h
diff --git a/src/arm/lithium-codegen-arm.h b/src/arm/lithium-codegen-arm.h
index 5b0c2af126f3cb54111db105dd426d4d20ac9675..da341762a569afcbdebe04814bf2442fb07b7702 100644
--- a/src/arm/lithium-codegen-arm.h
+++ b/src/arm/lithium-codegen-arm.h
@@ -65,6 +65,9 @@ class LCodeGen BASE_EMBEDDED {
   // Simple accessors.
   MacroAssembler* masm() const { return masm_; }
   CompilationInfo* info() const { return info_; }
+  Isolate* isolate() const { return info_->isolate(); }
+  Factory* factory() const { return isolate()->factory(); }
+  Heap* heap() const { return isolate()->heap(); }
 
   // Support for converting LOperands to assembler types.
   // LOperand must be a register.