Change parameter type of update_global_location_list from boolean to enum

Change parameter type of update_global_location_list from boolean to enum

Later we'll want a tristate, but for now, convert to an enum that maps 1-1
with the current boolean's true/false.

gdb/
2014-09-22  Pedro Alves  <palves@redhat.com>

	* breakpoint.c (enum ugll_insert_mode): New enum.
	(update_global_location_list)
	(update_global_location_list_nothrow): Change parameter type from
	boolean to enum ugll_insert_mode.  All callers adjusted.