Fix linking with --enable-targets=all:

Fix linking with --enable-targets=all:
* Makefile.in (ALL_TARGET_OBS): Add windows-tdep.o.
(HFILES_NO_SRCDIR): Add windows-tdep.h.
(ALLDEPFILES): Add windows-tdep.c.
* win32-tdep.h: Delete.
* windows-tdep.h: Rename from win32-tdep.h.
* win32-nat.h: Delete.
* windows-nat.h: Rename from win32-nat.h.
* win32-nat.c: Delete.
* windows-nat.c: Rename from win32-nat.c.
* win32-termcap.c: Delete.
* windows-termcap.c: Rename from win32-termcap.c.
* amd64-windows-nat.c: Handle rename from win32-nat.h -> windows-nat.h.
* configure.ac: Handle rename from win32-termcap.c -> windows-termcap.c.
* configure: Regenerate.
* gdb_curses.h: Change comment to reflect rename from win32-termcap.c ->
windows-termcap.c.
* i386-cygwin-tdep.c: Handle rename from win32-tdep.h -> windows-tdep.h.
* i386-windows-nat.c: Refect rename from win32-nat.h -> windows-nat.h.
* windows-nat.c: Ditto.  Also reflect rename from from win32-tdep.h ->
windows-tdep.h.
(win32_make_so): Handle cygwin compiler warning due to change of load_addr from
DWORD to LPVOID.
(handle_load_dll): Use %p in format string to properly print address and avoid
a compiler warning.
(DEBUG_EXCEPTION_SIMPLE): Ditto.
(handle_exception): Ditto.
* windows-tdep.c: Handle rename from win32-tdep.h -> windows-tdep.h.
* config/i386/cygwin.mh: Handle rename from win32-nat.o -> windows-nat.o.
* config/i386/mingw.mh: Ditto.
* config/i386/mingw64.mh: Ditto.