sra: Only verify sizes of scalar accesses (PR 93845)

sra: Only verify sizes of scalar accesses (PR 93845)

the testcase is another example - in addition to recent PR 93516 - where
the SRA access verifier is confused by the fact that get_ref_base_extent
can return different sizes for the same type, depending whether they are
COMPONENT_REF or not.  In the previous bug I decided to keep the
verifier check for aggregate type even though it is not really important
and instead avoid easily detectable type-within-the-same-type situation.
This testcase is however a result of a fairly random looking type cast
and so cannot be handled in the same way.

Because the check is not really important for aggregates, this patch
simply disables it for non-register types.

2020-02-21  Martin Jambor  <mjambor@suse.cz>

	PR tree-optimization/93845
	* tree-sra.c (verify_sra_access_forest): Only test access size of
	scalar types.

	testsuite/
	* g++.dg/tree-ssa/pr93845.C: New test.