Use root array to load roots in generated ARM code....

src/assembler.cc

Index: src/assembler.cc
===================================================================
--- src/assembler.cc	(revision 2686)
+++ src/assembler.cc	(working copy)
@@ -563,6 +563,11 @@
 }
 
 
+ExternalReference ExternalReference::roots_address() {
+  return ExternalReference(Heap::roots_address());
+}
+
+
 ExternalReference ExternalReference::address_of_stack_guard_limit() {
   return ExternalReference(StackGuard::address_of_jslimit());
 }