Move common static helpers from codegen to the macro-assembler files.

src/arm/codegen-arm.h

Index: src/arm/codegen-arm.h
===================================================================
--- src/arm/codegen-arm.h	(revision 5806)
+++ src/arm/codegen-arm.h	(working copy)
@@ -279,10 +279,6 @@
     return inlined_write_barrier_size_ + 4;
   }
 
-  static MemOperand ContextOperand(Register context, int index) {
-    return MemOperand(context, Context::SlotOffset(index));
-  }
-
  private:
   // Type of a member function that generates inline code for a native function.
   typedef void (CodeGenerator::*InlineFunctionGenerator)
@@ -349,10 +345,6 @@
                                                JumpTarget* slow);
 
   // Expressions
-  static MemOperand GlobalObject()  {
-    return ContextOperand(cp, Context::GLOBAL_INDEX);
-  }
-
   void LoadCondition(Expression* x,
                      JumpTarget* true_target,
                      JumpTarget* false_target,