Fix compiler class initialization to properly deal with super classes

Also moving active parts of compiler_test to be oat tests including
IntMath and Invoke. Added an interface invocation test case to Invoke
test. Changed Compiler to CHECK that it is not used once the
Runtime::IsStarted, forcing some jni_compiler_test to have two phases,
one for compiling before Runtime::Start and one for JNI operations
after the Runtime::IsStarted.

Finally, fixed Class::CanPutArrayElementFromCode by removing
CanPutArrayElement and calling IsAssignableFrom directly.

Change-Id: I52ca4dbc0e02db65f274ccc3ca7468dce365a44e
diff --git a/src/thread.cc b/src/thread.cc
index 9525a1c..153f20f 100644
--- a/src/thread.cc
+++ b/src/thread.cc
@@ -1053,6 +1053,7 @@
 
   virtual void VisitFrame(const Frame& frame, uintptr_t pc) {
     // We want to skip frames up to and including the exception's constructor.
+    DCHECK(gThrowable != NULL);
     if (skipping_ && !gThrowable->IsAssignableFrom(frame.GetMethod()->GetDeclaringClass())) {
       skipping_ = false;
     }