Use compilation info isolate pointer in lithium codegen.

src/ia32/lithium-codegen-ia32.h

Index: src/ia32/lithium-codegen-ia32.h
diff --git a/src/ia32/lithium-codegen-ia32.h b/src/ia32/lithium-codegen-ia32.h
index a6acd7de197709d8d40fd4fa11c6af71182faaf4..d06603c542f95f02b1fa6220b0584342ec7a2d14 100644
--- a/src/ia32/lithium-codegen-ia32.h
+++ b/src/ia32/lithium-codegen-ia32.h
@@ -68,6 +68,9 @@ 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.
   Operand ToOperand(LOperand* op) const;