Reduce namespace pollution.

This leaves us with just the mspace stuff and three libdex functions to clean
up. We deliberately expose the JII API, and I don't think there's anything we
can really do about the art_..._from_code stuff (and at least that starts with
"art_").

Change-Id: I77e58e8330cd2afeb496642302dfe3311e68091a
diff --git a/src/compiler/codegen/arm/ArchFactory.cc b/src/compiler/codegen/arm/ArchFactory.cc
index a68727f..14758b8 100644
--- a/src/compiler/codegen/arm/ArchFactory.cc
+++ b/src/compiler/codegen/arm/ArchFactory.cc
@@ -22,6 +22,8 @@
  *
  */
 
+namespace art {
+
 STATIC ArmLIR* genUnconditionalBranch(CompilationUnit*, ArmLIR*);
 STATIC ArmLIR* genConditionalBranch(CompilationUnit*, ArmConditionCode,
                                     ArmLIR*);
@@ -110,3 +112,5 @@
     oatInsertGrowableList(&cUnit->throwLaunchpads, (intptr_t)tgt);
     return branch;
 }
+
+}  // namespace art