8af8355c3f72500986f6f10b62714b228d6f35ee breaks minibuffer echo with Lucid

[Dmitry Antipov]

To reproduce:

1) Rewind tree to 8af8355c3f72500986f6f10b62714b228d6f35ee (git checkout 
8af8355c3f72500986f6f10b62714b228d6f35ee -b test)
2) Configure with ../emacs/configure --without-all --with-x-toolkit=lucid and 
compile
3) Run Emacs as ./src/emacs -Q --eval '(progn (menu-bar-mode 0) (tool-bar-mode 
0) (scroll-bar-mode -1))'
4) Type M-x and look at the minibuffer. It remains empty, but 'M-x' should be 
displayed.

At 6cd2629bd1b3ce77d29ac28e29237c94a4197116, minibuffer behaves as expected.

Dmitry