PR middle-end/93200 - spurious -Wstringop-overflow due to assignment vectorization to multiple members

PR middle-end/93200 - spurious -Wstringop-overflow due to assignment vectorization to multiple members
PR fortran/92956 - 'libgomp.fortran/examples-4/async_target-2.f90' fails with offloading due to bogus -Wstringop-overflow warning

gcc/testsuite/ChangeLog:

	PR middle-end/93200
	* gcc.dg/Wstringop-overflow-30.c: New test.

gcc/ChangeLog:

	PR middle-end/93200
	PR fortran/92956
	* builtins.c (compute_objsize): Avoid handling MEM_REFs of vector type.

From-SVN: r280041