opts: fix handling of -fpatchable-function-entries option

opts: fix handling of -fpatchable-function-entries option

gcc/ChangeLog:

	PR lto/98971
	* cfgexpand.c (pass_expand::execute): Parse per-function option
	flag_patchable_function_entry and use it.
	* common.opt: Remove function_entry_patch_area_size and
	function_entry_patch_area_start global variables.
	* opts.c (parse_and_check_patch_area): New function.
	(common_handle_option): Use it.
	* opts.h (parse_and_check_patch_area): New function.
	* toplev.c (process_options): Parse and use
	function_entry_patch_area_size.