While with GNU sed the optional backup suffix is given directly as part of the
-i[SUFFIX] (or --in-place[=SUFFIX]) argument, on macOS it must unconditionally
be given as a (potentially empty) argument following the -i argument.  That
means that on macOS the -e that happens to follow the -i in these sed
invocations (and that happens to not be necessary to introduce the following
script in these invocations) was mistaken as the backup suffix, causing creation
of pointless workdir/CustomTarget/*/generated/tokens.cxx-e backup files.

Change-Id: Icd865c76139afa348d03813eb83653afd7221a0e
Reviewed-on: https://gerrit.libreoffice.org/66491
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>