gdb/

gdb/
	Fix DW_AT_accessibility compatibility with gcc-4.6+.
	* dwarf2read.c: Include ctype.h.
	(producer_is_gxx_lt_4_6, dwarf2_default_access_attribute): New
	functions.
	(dwarf2_add_field): Fix new_field->accessibility by calling
	dwarf2_default_access_attribute.  Restructure setting accessibility
	vs. virtuality.
	(dwarf2_add_member_fn): New variable accessibility.  Fix fnp
	is_private and is_protected by calling
	dwarf2_default_access_attribute.