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/IntermediateRep.cc b/src/compiler/IntermediateRep.cc
index a7da037..c39aed3 100644
--- a/src/compiler/IntermediateRep.cc
+++ b/src/compiler/IntermediateRep.cc
@@ -17,6 +17,8 @@
 #include "Dalvik.h"
 #include "CompilerInternals.h"
 
+namespace art {
+
 /* Allocate a new basic block */
 BasicBlock* oatNewBB(BBType blockType, int blockId)
 {
@@ -122,3 +124,5 @@
     currentLIR->next = newLIR;
     newLIR->next->prev = newLIR;
 }
+
+}  // namespace art