leim/leim-ext.el not used on Windows

[Juanma Barranquero]

In leim/makefile.in, leim-list.el depends on leim-ext.el, and
non-empty, non-comment lines of leim-ext.el are appended to
leim-list.el.

However, leim/makefile.w32-in does not do that (in fact it does not
mention leim-ext.el at all).

Any easy way to add this to leim/makefile.w32-in without sed, or do we
finally add sed to the required tools for Windows builds?

                   /L/e/k/t/u