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/Ralloc.h b/src/compiler/codegen/Ralloc.h
index fee0e9a..e72cdcb 100644
--- a/src/compiler/codegen/Ralloc.h
+++ b/src/compiler/codegen/Ralloc.h
@@ -16,6 +16,7 @@
 
 #ifndef ART_SRC_COMPILER_RALLOC_H_
 #define ART_SRC_COMPILER_RALLOC_H_
+
 /*
  * This file contains target independent register alloction support.
  */
@@ -25,6 +26,8 @@
 #include "../Dataflow.h"
 #include "arm/ArmLIR.h"
 
+namespace art {
+
 /*
  * Return most flexible allowed register class based on size.
  * Bug: 2813841
@@ -237,4 +240,7 @@
 extern void oatDumpFPRegPool(CompilationUnit* cUint);
 extern bool oatCheckCorePoolSanity(CompilationUnit* cUnit);
 extern RegisterInfo* oatGetRegInfo(CompilationUnit* cUnit, int reg);
+
+}  // namespace art
+
 #endif // ART_SRC_COMPILER_RALLOC_H_