gdb/testsuite: add regression test for per-objfile typeprinters

gdb/testsuite: add regression test for per-objfile typeprinters

PR python/17136 reported an unhandled exception when using typeprinters
only valid on some objfiles, rather than being a global typeprinter. The
fix was accepted without a regression test, and we've been carrying one
out-of-tree for a while but I think it's worth upstreaming. The code
itself was developed by Jan Kratochvil.

Co-Authored-By: Jan Kratochvil <jkratochvil@azul.com>
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=17136
Reviewed-By: Andrew Burgess <aburgess@redhat.com>
Approved-By: Tom Tromey <tom@tromey.com>