7114095: G1: assert(obj == oopDesc::load_decode_heap_oop(p)) failed: p should still be pointing to obj
Summary: As a result of  the changes for 4965777, the G1 reference field scanning closure could be applied to the discovered field of a reference object twice. The failing assert is too strong if the result of the first application of the closure is stolen, and the referenced object, evacuated by another worker thread.
Reviewed-by: ysr, tonyp