PR c/20402
* c-parser.c (c_parser_struct_or_union_specifier): Don't fall
through into call to parser_xref_tag after parse error.
(c_parser_struct_declaration): Consistently return NULL_TREE on
error.
testsuite:
* gcc.dg/noncompile/920923-1.c: Detail expected diagnostics for
new parser.
From-SVN: r96363
