C++ Mode: Fix incoorect background fontification of <

C++ Mode: Fix incoorect background fontification of <

Where c-record-found-types gets "bound" to itself, we postpone the calling of
c-fontify-new-type on possible new found types until these are confirmed by
the return from the function tentatively finding these types, for exmaple
c-forward-<>-arglist.  We check this "binding" by testing the value of
c-record-found-types.

Correct the background fontification algorithm.

* lisp/progmodes/cc-engine.el (c-record-found-types): Move the definition to
earlier in the file.
(c-add-type-1): Check additionally c-record-found-types is nil before calling
c-fontify-new-found-type.
(c-forward-<>-arglist, c-forward-type): On return from a function which
collects found types in c-record-found-types, call c-fontify-new-found-types
for each such type.

* lisp/progmodes/c-fonts.el (c-force-redisplay): Actually fontify the new
found type.
(c-fontify-new-found-type): Test for font-lock-mode being enabled.  Remove the
spurious condition on the `fontified' text property being nil before causing
c-force-redisplay to get called.