dbxout.c (dbxout_init): If DBX_OUTPUT_GCC_MARKER is defined, use it instead of blindly generating a .stabs.

	* dbxout.c (dbxout_init): If DBX_OUTPUT_GCC_MARKER is defined,
	use it instead of blindly generating a .stabs.
	* xcoffout.h: Define DBX_OUTPUT_GCC_MARKER so we put the type
	in the right place.
	* xcoffout.c: Don't bother defining default for N_CATCH.
	(UNKNOWN_STAB): Use internal_error.
	(stab_to_sclass): Remove now-unnecessary aborts.
	Remove #if 0'ed case N_BROWS.  Add #ifdef N_OPT block.

From-SVN: r41404