[test][Interpreter] preconcurrency_conformances_with_legacy_isSameExecutor: make work under remote-run
Three related fixes for running this test against a remote target:
- Set libInterface.dylib and libTypes.dylib install_names to
@executable_path/lib<X>.dylib so dyld can resolve them next to the
binary regardless of the build host.
- Pass both dylib paths as trailing positional args to each
%target-run invocation so remote-run rsyncs them alongside the
binary. The test binaries ignore the extra argv slots.
- Prefix SWIFT_IS_CURRENT_EXECUTOR_LEGACY_MODE_OVERRIDE with %env- so
it crosses into the remote process. Without the prefix it is set
on the local lit shell only and never reaches the program that
actually runs.