Fix fontification of first item in CC Mode macro without parentheses

Fix fontification of first item in CC Mode macro without parentheses

* lisp/progmodes/cc-engine.el (c-find-decl-prefix-search): Handle the new
matching possibility (of a #define construct) in the new
c-decl-prefix-or-start-re.
(c-find-decl-spots): Allow the initial search for an in-macro starting point
settle on the # of #define, to facilitate the regexp matching in
c-find-decl-prefix-search.

* lisp/progmodes/cc-langs.el (c-anchored-hash-define-no-parens): New lang
const.
(c-literal-start-regexp): Correct what was always supposed to be a "generic
string" regexp element.
(c-decl-prefix-or-start-re): Enhance also to match "#define <identifier>".
(c-dposr-cpp-macro-depth): New lang variable and lang constant.