Reapply ARM root array change to reduce const pool size...

src/arm/macro-assembler-arm.h

Index: src/arm/macro-assembler-arm.h
===================================================================
--- src/arm/macro-assembler-arm.h	(revision 2740)
+++ src/arm/macro-assembler-arm.h	(working copy)
@@ -89,6 +89,10 @@
   void Ret(Condition cond = al);
   // Jumps to the label at the index given by the Smi in "index".
   void SmiJumpTable(Register index, Vector<Label*> targets);
+  // Load an object from the root table.
+  void LoadRoot(Register destination,
+                Heap::RootListIndex index,
+                Condition cond = al);
 
   // Sets the remembered set bit for [address+offset], where address is the
   // address of the heap object 'object'.  The address must be in the first 8K