ART: Clean up compiler

Clean up the compiler: less extern functions, dis-entangle
compilers, hide some compiler specifics, lower global includes.

Change-Id: Ibaf88d02505d86994d7845cf0075be5041cc8438
diff --git a/compiler/dex/post_opt_passes.h b/compiler/dex/post_opt_passes.h
index a1b0df4..550d254 100644
--- a/compiler/dex/post_opt_passes.h
+++ b/compiler/dex/post_opt_passes.h
@@ -17,6 +17,7 @@
 #ifndef ART_COMPILER_DEX_POST_OPT_PASSES_H_
 #define ART_COMPILER_DEX_POST_OPT_PASSES_H_
 
+#include "dex/quick/mir_to_lir.h"
 #include "compiler_internals.h"
 #include "pass_me.h"