semantics.c (finish_switch_cond): Handle error cases gracefully.

semantics.c (finish_switch_cond): Handle error cases gracefully.

        * semantics.c (finish_switch_cond): Handle error cases gracefully.
        Detected by g++.law/enum5.C
        * typeck.c (build_modify_expr): Check for errors after resolving
        offsets. Detected by g++.brendan/static1.C
        * decl.c (complete_array_type): Ignore initial_value if it is an
        error. Detected by g++.benjamin/17930.C
        * typeck2.c (process_init_constructor): Return error if one argument
        is in error. Detected by g++.benjamin/13478.C

From-SVN: r25740