Depessimize bits of CC Mode for long C macros.

Depessimize bits of CC Mode for long C macros.

* lisp/progmodes/cc-engine.el (c-end-of-macro): Check for being in a
degenerate zero length "macro", when setting the macro cache.
(c-determine-+ve-limit): Add in a missing goto-char form for when start-pos is
non-nil.
(c-back-over-member-initializers): Add a search limit parameter.

* lisp/progmodes/cc-fonts.el (c-get-fontification-context): Add a search limit
to c-go-up-list-backward.
(c-font-lock-cut-off-declarators): Add a search limit to
c-back-over-member-initializers.

* lisp/progmodes/cc-mode.el (c-before-change-check-unbalanced-strings): Don't
set c-new-END to the end of logical line (which might be a long macro).
(c-after-change-mark-abnormal-strings): Calculate end-hwm in place of the
setting of c-new-END (above).  Use this as a search limit rather than
c-new-END.