ART: Some Quick cleanup

Make several fields const in CompilationUnit. May benefit some Mir2Lir
code that repeats tests, and in general immutability is good.

Remove compiler_internals.h and refactor some other headers to reduce
overly broad imports (and thus forced recompiles on changes).

Change-Id: I898405907c68923581373b5981d8a85d2e5d185a
diff --git a/compiler/dex/verified_method.cc b/compiler/dex/verified_method.cc
index 93e9a51..21e965d 100644
--- a/compiler/dex/verified_method.cc
+++ b/compiler/dex/verified_method.cc
@@ -23,20 +23,13 @@
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "dex_file.h"
-#include "dex_instruction.h"
 #include "dex_instruction-inl.h"
-#include "base/mutex.h"
-#include "base/mutex-inl.h"
-#include "mirror/art_method.h"
 #include "mirror/art_method-inl.h"
-#include "mirror/class.h"
 #include "mirror/class-inl.h"
-#include "mirror/dex_cache.h"
 #include "mirror/dex_cache-inl.h"
-#include "mirror/object.h"
 #include "mirror/object-inl.h"
+#include "utils.h"
 #include "verifier/dex_gc_map.h"
-#include "verifier/method_verifier.h"
 #include "verifier/method_verifier-inl.h"
 #include "verifier/reg_type-inl.h"
 #include "verifier/register_line-inl.h"