Bootstrapping trunk fails on Windows

[martin rudalics]

I haven't been bootstrapping trunk for quite some while.  It currently
fails with MinGW as:

make[3]: Leaving directory `/c/emacs/trunk/lib'
make[2]: Leaving directory `/c/emacs/trunk/lib'
make -C lib-src all
make[2]: Entering directory `/c/emacs/trunk/lib-src'
gcc -std=gnu99  -c -mtune=pentium4    -I. -I../src -I../lib -I. -I./../src 
-I./../lib   -O0 -g3 ./../src/regex.c
In file included from ../src/config.h:1811:0,
                 from ./../src/regex.c:50:
../src/conf_post.h:32:27: fatal error: ms-w32.h: No such file or directory
compilation terminated.
make[2]: *** [regex.o] Error 1
make[2]: Leaving directory `/c/emacs/trunk/lib-src'
make[1]: *** [lib-src] Error 2
make[1]: Leaving directory `/c/emacs/trunk'
make: *** [bootstrap] Error 2

Thanks for any advice, martin