gdb

gdb
	PR symtab/11919:
	* gdbtypes.c (lookup_struct_elt_type): Clean up error emission.
	* parse.c (parse_field_expression): Use RETURN_MASK_ERROR.  Move
	name-copying lower.  Document exception behavior.
	* completer.c (expression_completer): Catch exceptions from
	parse_field_expression.
gdb/testsuite
	PR symtab/11919:
	* gdb.base/completion.exp: Add test.