Fix -freport-bug patch.

Fix -freport-bug patch.

	gcc/
	* gcc.c (try_generate_repro): Remove argument "prog".  Change all
	users.
	(run_attempt): Handle errors of "pex_run" invocation.

Fixes bootstrap failure/compiler warnings:

    [...]
    ../../master/gcc/gcc.c: In function 'attempt_status run_attempt(const char**, const char*, const char*, int, int)':
    ../../master/gcc/gcc.c:6319:15: error: variable 'errmsg' set but not used [-Werror=unused-but-set-variable]
       const char *errmsg;
                   ^
    ../../master/gcc/gcc.c: At global scope:
    ../../master/gcc/gcc.c:6412:33: error: unused parameter 'prog' [-Werror=unused-parameter]
     try_generate_repro (const char *prog, const char **argv)
                                     ^
    cc1plus: all warnings being treated as errors
    Makefile:1040: recipe for target 'gcc.o' failed
    make[3]: *** [gcc.o] Error 1
    make[3]: Leaving directory '/media/erich/home/thomas/tmp/gcc/hurd/master.build/gcc'
    Makefile:4285: recipe for target 'all-stage2-gcc' failed
    make[2]: *** [all-stage2-gcc] Error 2
    make[2]: Leaving directory '/media/erich/home/thomas/tmp/gcc/hurd/master.build'
    Makefile:21561: recipe for target 'stage2-bubble' failed
    make[1]: *** [stage2-bubble] Error 2
    make[1]: Leaving directory '/media/erich/home/thomas/tmp/gcc/hurd/master.build'
    Makefile:892: recipe for target 'all' failed
    make: *** [all] Error 2

From-SVN: r215644