TBAA, separate JRuntime and ConstJObject.

This change can eliminate redundant virtual table load.

Also, fix comment.

Change-Id: I9deb9979eadce6ad728b6582cef80001e3a7039e
diff --git a/src/compiler_llvm/jni_compiler.cc b/src/compiler_llvm/jni_compiler.cc
index 1fa0ce7..357d50d 100644
--- a/src/compiler_llvm/jni_compiler.cc
+++ b/src/compiler_llvm/jni_compiler.cc
@@ -90,7 +90,7 @@
         irb_.LoadFromObjectOffset(method_object_addr,
                                   Method::DeclaringClassOffset().Int32Value(),
                                   irb_.getJObjectTy(),
-                                  kTBAAJRuntime);
+                                  kTBAAConstJObject);
   }
   // Actual argument (ignore method and this object)
   arg_begin = arg_iter;