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

src/arm/macro-assembler-arm.h

Index: src/arm/macro-assembler-arm.h
===================================================================
--- src/arm/macro-assembler-arm.h	(revision 5806)
+++ src/arm/macro-assembler-arm.h	(working copy)
@@ -727,6 +727,16 @@
 // -----------------------------------------------------------------------------
 // Static helper functions.
 
+static MemOperand ContextOperand(Register context, int index) {
+  return MemOperand(context, Context::SlotOffset(index));
+}
+
+
+static inline MemOperand GlobalObjectOperand()  {
+  return ContextOperand(cp, Context::GLOBAL_INDEX);
+}
+
+
 #ifdef GENERATED_CODE_COVERAGE
 #define CODE_COVERAGE_STRINGIFY(x) #x
 #define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)