Instead of passing file dependencies individually, assume that the
whole content of the unique test directory is a dependency. This
simplifies the test harness significantly, by making %T the directory
that contains everything required to run a test. This also removes the
need for the %{file_dependencies} substitution, which is removed by this
patch.
Furthermore, this patch also changes the harness to execute tests locally
inside %T, so as to avoid creating a separate directory for no purpose.
When running on remote hosts, we need the whole `echo 123 | %t.exe` command
to run on the remote host. Thus, we need to escape the pipe to make sure
the command is treated as `{ echo 123 | %t.exe } > %t.out` instead of
`{ echo 123 } | %t.exe > %t.out`m where only `echo 123` is run on the
remote host.
Louis Dionne