Final target Rust programs are currently not picked up and
symlinked/copied to ${objdir}/dist/bin because the RUST_PROGRAMS output
variable is missing from the if-condition.
This change causes Rust binaries from RUST_PROGRAMS to be placed alongside
the other final target programs.
MozReview-Commit-ID: 5OIH1UMmCq2
--HG--
extra : rebase_source : cfcff21e9371b920c895ad27df344008962d7471