mesa/glthread: restore the dispatch table when incompatible gl calls are detected

mesa/glthread: restore the dispatch table when incompatible gl calls are detected

While a context only has a single glthread, the context itself can be
attached to several threads. Therefore the dispatch table must be
updated in all threads before the destruction of glthread. In others
words, glthread can only be destroyed safely when the context is deleted.

Fixes remaining crashes in the glx-multithread-makecurrent* tests.

V2: (Timothy Arceri) updated gl_API.dtd marshal_fail description.

Signed-off-by: Gregory Hainaut <gregory.hainaut@gmail.com>
Acked-by: Timothy Arceri <tarceri@itsqueeze.com>
Acked-by: Marek Olšák <maraeo@gmail.com>
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
Tested-by: Mike Lothian <mike@fireburn.co.uk>