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/CompilerUtility.h b/src/compiler/CompilerUtility.h
index 0a7d079..d7612ff 100644
--- a/src/compiler/CompilerUtility.h
+++ b/src/compiler/CompilerUtility.h
@@ -19,6 +19,8 @@
 
 #include "Dalvik.h"
 
+namespace art {
+
 /* Each arena page has some overhead, so take a few bytes off */
 #define ARENA_DEFAULT_SIZE ((256 * 1024) - 256)
 
@@ -112,4 +114,6 @@
 const char* oatGetShortyFromTargetIdx(CompilationUnit*, int);
 void oatDumpRegLocTable(struct RegLocation*, int);
 
+}  // namespace art
+
 #endif  // ART_SRC_COMPILER_COMPILER_UTILITY_H_