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/verification_results.cc b/compiler/dex/verification_results.cc
index 4daed67..4ff173d 100644
--- a/compiler/dex/verification_results.cc
+++ b/compiler/dex/verification_results.cc
@@ -16,15 +16,14 @@
 
 #include "verification_results.h"
 
+#include "base/logging.h"
 #include "base/stl_util.h"
-#include "base/mutex.h"
 #include "base/mutex-inl.h"
 #include "driver/compiler_driver.h"
 #include "driver/compiler_options.h"
 #include "thread.h"
 #include "thread-inl.h"
 #include "verified_method.h"
-#include "verifier/method_verifier.h"
 #include "verifier/method_verifier-inl.h"
 
 namespace art {