Move JNI compiler tests to use pure JNI.

Implement JNI upcalls for x86.
Fix off by 1 bug in JNI calling convention for x86.
Fix bugs in ARM JNI upcalls.
Straw man JNI invoke nonvirtual implementations.
Match va_start with va_end in JNI internals.

Change-Id: I64d62eca41ac726ae0d007c1f41d2193db5be82e
diff --git a/src/object.h b/src/object.h
index 2384fde..c78103b 100644
--- a/src/object.h
+++ b/src/object.h
@@ -375,8 +375,8 @@
     return declaring_class_;
   }
 
-  static MemberOffset ClassOffset() {
-    return MemberOffset(OFFSETOF_MEMBER(Method, klass_));
+  static MemberOffset DeclaringClassOffset() {
+    return MemberOffset(OFFSETOF_MEMBER(Method, declaring_class_));
   }
 
   // Returns true if the method is declared public.