Use enclosing object size if it's smaller than member [PR 101475].

Use enclosing object size if it's smaller than member [PR 101475].

Resolves:
PR middle-end/101475 - missing -Wstringop-overflow storing a compound literal

gcc/ChangeLog:

	PR middle-end/101475
	* pointer-query.cc (handle_component_ref): Use the size of
	the enclosing object if it's smaller than the member.

gcc/testsuite/ChangeLog:

	PR middle-end/101475
	* gcc.dg/Wstringop-overflow-15.c: Remove xfails.
	* gcc.dg/Wstringop-overflow-68.c: Adjust, remove xfails.
	* gcc.dg/Wstringop-overflow-88.c: New test.