gdb/

gdb/
	Fix printed anonymous struct name.
	* dwarf2read.c (fixup_partial_die): Handle for anonymous structs also
	DW_TAG_interface_type.  Strip for anonymous structs any prefixes.
	(anonymous_struct_prefix): New function.
	(determine_prefix): New variables retval.  Call anonymous_struct_prefix.
	(dwarf2_name): Strip for anonymous structs any prefixes.

gdb/testsuite/
	Fix printed anonymous struct name.
	* gdb.cp/anon-struct.exp (print type of X::t2): New test.