re PR driver/22600 (Exit code should be different from 1 for internal compiler error)

re PR driver/22600 (Exit code should be different from 1 for internal compiler error)

	PR driver/22600
	* system.h (ICE_EXIT_CODE): New macro.
	* diagnostic.c (diagnostic_count_diagnostic): Exit with ICE_EXIT_CODE.
	(diagnostic_action_after_output): Likewise.
	* gcc.c (fatal_ice): New function.
	(execute): Use it instead of fatal.
	(fancy_abort): Likewise.
	* doc/invoke.texi (-pass-exit-codes): Document return code for ICEs.

	* fortran/error.c (gfc_fatal_error): Return ICE_EXIT_CODE instead of 4.

From-SVN: r112292