branch emacs-28 build broken on MinGW64 with gcc 11

[wsw0108@qq.com]

The error messages as below:

$ make
make -C nt all
make[1]: Entering directory '/d/GitHub/emacs/nt'
make[1]: Nothing to be done for 'all'.
make[1]: Leaving directory '/d/GitHub/emacs/nt'
make -C lib all
make[1]: Entering directory '/d/GitHub/emacs/lib'
make[1]: Nothing to be done for 'all'.
make[1]: Leaving directory '/d/GitHub/emacs/lib'
make -C lib-src all
make[1]: Entering directory '/d/GitHub/emacs/lib-src'
  CC       ntlib.o
In file included from ../lib/time.h:44,
                 from ntlib.c:35:
../lib/unistd.h:624:3: error: #error "Please include config.h first."
  624 |  #error "Please include config.h first."
      |   ^~~~~
../lib/unistd.h:626:24: error: expected ';' before 'extern'
  626 | _GL_INLINE_HEADER_BEGIN
      |                        ^
      |                        ;
In file included from ../lib/time.h:47,
                 from ntlib.c:35:
E:/msys64/mingw64/x86_64-w64-mingw32/include/time.h:24:9: error: expected '=', ',', ';', 'asm' or '__attribute__' before '#pragma'
   24 | #pragma pack(push,_CRT_PACKING)
      |         ^~~~
ntlib.c:417:1: error: conflicting types for 'lstat'; have 'int(const char *, struct _stati64 *)'
  417 | lstat (const char * path, struct stat * buf)
      | ^~~~~
In file included from ../lib/sys/stat.h:47,
                 from ntlib.c:38:
D:/GitHub/emacs/nt/inc/sys/stat.h:162:33: note: previous declaration of 'lstat' with type 'int(const char *, struct stat *)'
  162 | int __cdecl __MINGW_NOTHROW     lstat (const char*, struct stat*);
      |                                 ^~~~~
make[1]: *** [Makefile:418: ntlib.o] Error 1
make[1]: Leaving directory '/d/GitHub/emacs/lib-src'
make: *** [Makefile:436: lib-src] Error 2