gdb can't print a variable named like a C keyword

Programs in a custom language whose DWARF says DW_LANG_C get their gdb expressions parsed as C. A source variable named signed, unsigned, int, char, long or struct makes print signed fail or print something else, while other variables print fine. In a gdb-driven debug test this shows up as a missing $N = line and looks like a printer bug. Rename the variable in the test, or quote it the way your gdb build allows. Related: a gdb pretty-printer with display_hint 'array' prints to_string followed by its children, so a printer that wants a single line, like bytes then the text they spell, needs a separate printer class with only to_string, chosen in the lookup function.