ART: Clean up art_method.h

Clean up the header. Fix up other headers including the -inl file,
in an effort to prune the include graph. Fix broken transitive
includes by making includes explicit. Introduce new -inl files
for method handles and reference visiting.

Test: source build/envsetup.sh && lunch aosp_angler-userdebug && mmma art
Test: source build/envsetup.sh && lunch aosp_mips64-userdebug && mmma art
Change-Id: I8f60f1160c2a702fdf3598149dae38f6fa6bc851
diff --git a/compiler/optimizing/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc
index 60790e5..2dcc12e 100644
--- a/compiler/optimizing/instruction_simplifier.cc
+++ b/compiler/optimizing/instruction_simplifier.cc
@@ -16,6 +16,8 @@
 
 #include "instruction_simplifier.h"
 
+#include "art_method-inl.h"
+#include "class_linker-inl.h"
 #include "escape.h"
 #include "intrinsics.h"
 #include "mirror/class-inl.h"