bug#69888: 30.0.50; Cygw32 build break

[Kazuhiro Ito <kzhr@d1.dion.ne.jp>]

Cygw32 build fails on  master


$ make
(snip)
  CC       w32xfns.o
In file included from ../../../emacs/trunk/src/w32xfns.c:35:
/usr/include/w32api/wtsapi32.h:147:16: error: redeclaration of ‘enum _WTS_VIRTUAL_CLASS’
  147 |   typedef enum _WTS_VIRTUAL_CLASS {
      |                ^~~~~~~~~~~~~~~~~~
../../../emacs/trunk/src/w32xfns.c:30:14: note: originally defined here
   30 | typedef enum _WTS_VIRTUAL_CLASS {
      |              ^~~~~~~~~~~~~~~~~~
In file included from ../../../emacs/trunk/src/w32xfns.c:35:
/usr/include/w32api/wtsapi32.h:148:5: error: redeclaration of enumerator ‘WTSVirtualClientData’
  148 |     WTSVirtualClientData,WTSVirtualFileHandle
      |     ^~~~~~~~~~~~~~~~~~~~
../../../emacs/trunk/src/w32xfns.c:31:3: note: previous definition of ‘WTSVirtualClientData’ with type ‘enum _WTS_VIRTUAL_CLASS’
   31 |   WTSVirtualClientData,
      |   ^~~~~~~~~~~~~~~~~~~~
In file included from ../../../emacs/trunk/src/w32xfns.c:35:
/usr/include/w32api/wtsapi32.h:148:26: error: redeclaration of enumerator ‘WTSVirtualFileHandle’
  148 |     WTSVirtualClientData,WTSVirtualFileHandle
      |                          ^~~~~~~~~~~~~~~~~~~~
../../../emacs/trunk/src/w32xfns.c:32:3: note: previous definition of ‘WTSVirtualFileHandle’ with type ‘enum _WTS_VIRTUAL_CLASS’
   32 |   WTSVirtualFileHandle
      |   ^~~~~~~~~~~~~~~~~~~~
../../../emacs/trunk/src/w32xfns.c: In function ‘drain_message_queue’:
../../../emacs/trunk/src/w32xfns.c:431:13: warning: implicit declaration of function ‘reset_w32_kbdhook_state’ [-Wimplicit-function-declaration]
  431 |             reset_w32_kbdhook_state ();
      |             ^~~~~~~~~~~~~~~~~~~~~~~
../../../emacs/trunk/src/w32xfns.c:431:13: warning: nested extern declaration of ‘reset_w32_kbdhook_state’ [-Wnested-externs]

it seems that _WTS_VIRTUAL_CLASS is defines in Cygwin's headaer and
reset_w32_kbdhook_state is not defined on Cygw32 build.

-- 
Kazuhiro Ito