A generic jni method can be instrumented.

Fixes tracing 119-noimage-patchoat test.

Change-Id: Ifc9709b714dbad6e087d327fdde7a008e5e731d3
diff --git a/runtime/art_method.cc b/runtime/art_method.cc
index 3f17702..c1279bf 100644
--- a/runtime/art_method.cc
+++ b/runtime/art_method.cc
@@ -412,6 +412,13 @@
     if (class_linker->IsQuickResolutionStub(existing_entry_point)) {
       // We are running the generic jni stub, but the entry point of the method has not
       // been updated yet.
+      DCHECK_EQ(pc, 0u) << "Should be a downcall";
+      DCHECK(IsNative());
+      return nullptr;
+    }
+    if (existing_entry_point == GetQuickInstrumentationEntryPoint()) {
+      // We are running the generic jni stub, but the method is being instrumented.
+      DCHECK_EQ(pc, 0u) << "Should be a downcall";
       DCHECK(IsNative());
       return nullptr;
     }