* breakpoint.c (clear_momentary_breakpoints): Remove dead code

	* breakpoint.c (clear_momentary_breakpoints): Remove dead code
	that is referenced nowhere else.
	(set_breakpoint): Ditto.
	(do_enable_breakpoint): Created from enable_once_breakpoint
	with a couple of changes.
	(enable_breakpoint): Call do_enable_breakpoint with an appropriate
	bpdisp enum value to set disposition of breakpoint.
	(enable_once_breakpoint): Ditto.
	(enable_delete_breakpoint): Ditto.
	* breakpoint.h (clear_momentary_breakpoints): Remove prototype.
	* symtab.c (find_pc_line): Improve comments.
	* gdbtk.c: Fix a couple of misspellings.
	* xcoffread.c: Ditto.