Build Vim as a DLL with stubs

Vim is substantially smaller because vim.exe and gvim.exe are now
effectively the same binary. On Windows these must be distinct binaries
since they target the "console" and "windows" subsystems separately.
"vim -g" now works correctly, though "vim -g -f" still does not work.

Enabling VIMDLL requires enabling IME (probably a bug). I also noticed
vimrun.exe isn't stripped, nor does it need to be installed on the PATH.

Dockerfile

@@ -381,16 +381,12 @@ RUN patch -d.. -p1 <$PREFIX/src/vim-markdown-italics.patch \
  && ARCH= make -j$(nproc) -f Make_ming.mak \
  OPTIMIZE=SIZE STATIC_STDCPLUS=yes HAS_GCC_EH=no \
  UNDER_CYGWIN=yes CROSS=yes CROSS_COMPILE=$ARCH- \
- FEATURES=HUGE OLE=no IME=no NETBEANS=no WINDRES_FLAGS= \
- && ARCH= make -j$(nproc) -f Make_ming.mak \
- OPTIMIZE=SIZE STATIC_STDCPLUS=yes HAS_GCC_EH=no \
- UNDER_CYGWIN=yes CROSS=yes CROSS_COMPILE=$ARCH- \
- FEATURES=HUGE OLE=no IME=no NETBEANS=no WINDRES_FLAGS= \
- GUI=no vim.exe \
+ FEATURES=HUGE VIMDLL=yes NETBEANS=no WINDRES_FLAGS= \
+ && $ARCH-strip vimrun.exe \
  && rm -rf ../runtime/tutor/tutor.* \
  && cp -r ../runtime $PREFIX/share/vim \
- && cp gvim.exe vim.exe $PREFIX/share/vim/ \
- && cp vimrun.exe xxd/xxd.exe $PREFIX/bin \
+ && cp vimrun.exe gvim.exe vim.exe *.dll $PREFIX/share/vim/ \
+ && cp xxd/xxd.exe $PREFIX/bin \
  && printf '@set SHELL=\r\n@start "" "%%~dp0/../share/vim/gvim.exe" %%*\r\n' \
  >$PREFIX/bin/gvim.bat \
  && printf '@set SHELL=\r\n@"%%~dp0/../share/vim/vim.exe" %%*\r\n' \