re PR c/88928 (ICE segfault in check_address_or_pointer_of_packed_member since r268075)

2019-01-21  Bernd Edlinger  <bernd.edlinger@hotmail.de>

        PR c/88928
        * c-warn.c (check_alignment_of_packed_member): Add a boolean parameter
        for rvalue context.  Handle rvalues correctly.  Use min_align_of_type
        instead of TYPE_ALIGN.
        (check_address_or_pointer_of_packed_member): Handle rvalues coorrectly.
        Use min_align_of_type instead of TYPE_ALIGN_UNIT.  Check for NULL
        pointer from TYPE_STUB_DECL.

testsuite:
2019-01-21  Bernd Edlinger  <bernd.edlinger@hotmail.de>

        PR c/88928
        * c-c++-common/Waddress-of-packed-member-1.c: New test case.
        * gcc.dg/pr88928.c: New test case.

From-SVN: r268118