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/ArmLIR.h b/src/compiler/codegen/arm/ArmLIR.h
index 729e708..e77bed3 100644
--- a/src/compiler/codegen/arm/ArmLIR.h
+++ b/src/compiler/codegen/arm/ArmLIR.h
@@ -20,6 +20,8 @@
 #include "../../Dalvik.h"
 #include "../../CompilerInternals.h"
 
+namespace art {
+
 // Set to 1 to measure cost of suspend check
 #define NO_SUSPEND 0
 
@@ -882,4 +884,6 @@
 #define CHAIN_CELL_NORMAL_SIZE 12
 #define CHAIN_CELL_PREDICTED_SIZE 16
 
+}  // namespace art
+
 #endif  // ART_SRC_COMPILER_CODEGEN_ARM_ARMLIR_H_