For the same reason we disable shebang patching in these derivations,
we want to disable the patching of libtool scripts stdenv does.
Otherwise, libtool will install scripts into other packages that are
already "fixed", but for the environment libtool was built in. These
scripts won't be fixed properly by stdenv anymore, because it will
think they were already fixed.
This fixes the build of pkgsStatic.libwebp, which was failing because
its libtool script wasn't being patched properly.
Another problem "fixing" the scripts in the libtool package would
cause is that package tarballs generated on NixOS would contain
libtool scripts that didn't make sense on other distros.
I've tested this change by building pkgsStatic.libwebp, which now
works, as well as by testing the build of the bootstrap files for
mips64el to make sure that didn't regress from 97c43828fb
("fixLibtool(): patch ./configure, add `file` to common-path.nix").
4195ac320b