Fix a assertion raised by every exception with newer clang versions (>3.7) at least on ARM64:
../../../dlls/dbghelp/dwarf.c:1641: void dwarf2_parse_variable(dwarf2_subprogram_t *, struct symt_block *, dwarf2_debug_info_t *): Assertion `subpgm->func' failed.
Signed-off-by: André Hentschel <nerv@dawncrow.de>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>