Fixing structure of native frame for Generic JNI

This changes the layout of the callee-save frame used in generic
JNI to be consistent with the JNI compiler, that is, the SIRT is
inline (above the method reference). Now the location of the
"this" object is consistent.

Change-Id: Ibad0882680712cb640b4c70ada0229ef7cf4e62c
diff --git a/runtime/stack.cc b/runtime/stack.cc
index 15b288e..26b4de3 100644
--- a/runtime/stack.cc
+++ b/runtime/stack.cc
@@ -108,17 +108,11 @@
     return NULL;
   } else if (m->IsNative()) {
     if (cur_quick_frame_ != NULL) {
-      if (m->GetEntryPointFromQuickCompiledCode() == GetQuickGenericJniTrampoline()) {
-        UNIMPLEMENTED(ERROR) << "Failed to determine this object of native method: "
-            << PrettyMethod(m);
-        return nullptr;
-      } else {
-        StackIndirectReferenceTable* sirt =
-            reinterpret_cast<StackIndirectReferenceTable*>(
-                reinterpret_cast<char*>(cur_quick_frame_) +
-                m->GetSirtOffsetInBytes());
-        return sirt->GetReference(0);
-      }
+      StackIndirectReferenceTable* sirt =
+          reinterpret_cast<StackIndirectReferenceTable*>(
+              reinterpret_cast<char*>(cur_quick_frame_) +
+              m->GetSirtOffsetInBytes());
+      return sirt->GetReference(0);
     } else {
       return cur_shadow_frame_->GetVRegReference(0);
     }