Add tests for validating future C permerrors

The dg-error directives for gcc.dg/permerror-system.c can be generated
using (for the most part at least):

perl -ne 'print if s,.*(/\* \{ dg-error .*) } \*/$,$1 "" { target *-*-* } $. } */,' \
  < gcc/testsuite/gcc.dg/permerror-default.c

gcc/testsuite/

	* gcc.dg/permerror-default.c: New test.
	* gcc.dg/permerror-fpermissive.c: Likewise.
	* gcc.dg/permerror-fpermissive-nowarning.c: Likewise.
	* gcc.dg/permerror-gnu89-nopermissive.c: Likewise.
	No permerrors yet, so this matches gcc.dg/permerror-gnu89.c
	for now.
	* gcc.dg/permerror-gnu89-pedantic.c: New test.
	* gcc.dg/permerror-gnu89.c: Likewise.
	* gcc.dg/permerror-noerror.c: Likewise.
	* gcc.dg/permerror-nowarning.c: Likewise.
	* gcc.dg/permerror-pedantic.c: Likewise.
	* gcc.dg/permerror-system.c: Likewise.