C++ Mode - Fontify "class Foo {\n ~Foo() noexcept;" correctly

This fixes bug #49787.

* lisp/progmodes/cc-engine.el (c-forward-decl-or-cast-1): (In `if' form just
before CASE 8) Remove the (not ...) around the (looking-at
c-after-suffixed-type-maybe-decl-key).

* lisp/progmodes/cc-fonts.el (c-font-lock-complex-decl-prepare): Add
`c-not-decl' to the values of c-type which are erased at the start of a
fontification.

2 files changed, 4 insertions, 3 deletions

diff --git a/lisp/progmodes/cc-engine.el b/lisp/progmodes/cc-engine.el
index f46c909fea5..1139423a455 100644
--- a/lisp/progmodes/cc-engine.el
+++ b/lisp/progmodes/cc-engine.el
@@ -10571,8 +10571,8 @@ This function might do hidden buffer changes."
                         backup-maybe-typeless
                         (when c-recognize-typeless-decls
                           (or (not got-suffix)
-                              (not (looking-at
-                                    c-after-suffixed-type-maybe-decl-key))))))
+                              (looking-at
+                               c-after-suffixed-type-maybe-decl-key)))))
                ;; Got an empty paren pair and a preceding type that probably
                ;; really is the identifier.  Shift the type backwards to make
                ;; the last one the identifier.  This is analogous to the
diff --git a/lisp/progmodes/cc-fonts.el b/lisp/progmodes/cc-fonts.el
index 2495d21a10f..12bb3d37513 100644
--- a/lisp/progmodes/cc-fonts.el
+++ b/lisp/progmodes/cc-fonts.el
@@ -940,7 +940,8 @@ casts and declarations are fontified.  Used on level 2 and higher."
                         '(c-decl-arg-start
                           c-decl-end
                           c-decl-id-start
-                          c-decl-type-start)))
+                          c-decl-type-start
+                          c-not-decl)))
              (1- (point))
            pos)
          limit 'c-type)))