Added fixme comment. Removed the extra testcase. Added release note

Author: Abhinkop

clang/docs/ReleaseNotes.rst

@@ -284,6 +284,7 @@ Modified Compiler Flags
   ``rtdcall``. This new default CC only works for M68k and will use the new
   ``m68k_rtdcc`` CC on every functions that are not variadic. The ``-mrtd``
   driver/frontend flag has the same effect when targeting M68k.
+* ``-Wextra`` group flag now contains an adittional flag i.e, ``-Wcast-function-type``.
 
 Removed Compiler Flags
 -------------------------

clang/test/Sema/warn-cast-function-type-strict.c

@@ -39,5 +39,6 @@ void foo(void) {
   g = (f7 *)x; /* expected-warning {{cast from 'int (*)(long)' to 'f7 *' (aka 'int (*)(long, ...)') converts to incompatible function type}} */
   h = (f8 *)t;
   i = (f9 *)u;
+  // FIXME: return type qualifier should not be included in the function type . Warning should be absent after this issue is fixed. https://github.com/llvm/llvm-project/issues/39494 .
   j = (f10 *)v; /* expected-warning {{cast from 'const int (*)(int)' to 'f10 *' (aka 'int (*)(int)') converts to incompatible function type}} */
 }