Build failure on master, wrong pdmp file loaded

[Ulrich Mueller]

Today I am getting a build failure on master, bootstrap-emacs tries
to load its portable dump file from the installed location in
/usr/libexec/emacs/ which of course has the wrong checksum:

   make -C ../lisp compile-first EMACS="../src/bootstrap-emacs"
   make[2]: Entering directory 
'/tmp/portage/app-editors/emacs-28.0.9999/work/emacs/lisp'
   EMACSLOADPATH= '../src/bootstrap-emacs' -batch --no-site-file --no-site-lisp 
--eval '(setq load-prefer-newer t)'  -f batch-byte-compile 
emacs-lisp/macroexp.el
   desired fingerprint: 
d930cd08e3e5ab5bf87a844184483b9c4b361e3275403e685b30e8ce786a8545
   found fingerprint: 
634291831fdc4e7d29f86299e9f42fcebd422d615dc8061265dbf5b6a633fad2
   emacs: could not load dump file 
"/usr/libexec/emacs/28.0.50/x86_64-pc-linux-gnu/emacs.pdmp": not built for this 
Emacs executable

git bisect points to commit b9683230ec which is a one-line change in
faces.el (and looks innocent to me).

The revious revision 8c589c2583 builds fine. Both builds were done in an
ebuild environment, i.e., from a clean checkout.