Cross-platform cleanup in preparation of better ARM code for indexed load/store.

runtime/vm/flow_graph_compiler_x64.cc

Index: runtime/vm/flow_graph_compiler_x64.cc
===================================================================
--- runtime/vm/flow_graph_compiler_x64.cc	(revision 36449)
+++ runtime/vm/flow_graph_compiler_x64.cc	(working copy)
@@ -1575,10 +1575,10 @@
 }
 
 
-FieldAddress FlowGraphCompiler::ElementAddressForIntIndex(intptr_t cid,
-                                                          intptr_t index_scale,
-                                                          Register array,
-                                                          intptr_t index) {
+Address FlowGraphCompiler::ElementAddressForIntIndex(intptr_t cid,
+                                                     intptr_t index_scale,
+                                                     Register array,
+                                                     intptr_t index) {
   const int64_t disp =
       static_cast<int64_t>(index) * index_scale + DataOffsetFor(cid);
   ASSERT(Utils::IsInt(32, disp));
@@ -1604,10 +1604,10 @@
 }
 
 
-FieldAddress FlowGraphCompiler::ElementAddressForRegIndex(intptr_t cid,
-                                                          intptr_t index_scale,
-                                                          Register array,
-                                                          Register index) {
+Address FlowGraphCompiler::ElementAddressForRegIndex(intptr_t cid,
+                                                     intptr_t index_scale,
+                                                     Register array,
+                                                     Register index) {
   return FieldAddress(array,
                       index,
                       ToScaleFactor(index_scale),