7127687: MethodType leaks memory due to interning
Summary: Replace internTable with a weak-reference version.
Reviewed-by: sundar, forax, brutisso
Contributed-by: james.laskey@oracle.com
7129034: VM crash with a field setter method with a filterArguments
Summary: add null checks before unsafe calls that take a variable base reference; update unit tests
Reviewed-by: kvn, twisti