CC Mode: Fix bug in "state cache" invalidation function.
* lisp/progmodes/cc-engine.el (c-invalidate-state-cache-1): Rewrite part of it, following the code in c-parse-state-1, to get a proper setting of c-state-cache-good-pos.
* lisp/progmodes/cc-engine.el (c-invalidate-state-cache-1): Rewrite part of it, following the code in c-parse-state-1, to get a proper setting of c-state-cache-good-pos.