He says:
Update libtool to 1.3.3 and modify it's behaviour a bit. It now
behaves like a stock libtool unless we start sending one of three
flags:
--disable-ltlibs Don't install .la files
--release-suffix Add the release to the end of all the libs (like
GLib/GTK+)
--release-ignore Don't add the release to any libs.
PR: 13114