Revert: * Makefile.in (check/%.exp): Pass directory for GDB_PARALLEL.
Regressions, e.g.,
http://gdb-build.sergiodj.net/builders/Fedora-x86_64-m32/builds/1501
gdb/testsuite/ChangeLog:
Revert:
* Makefile.in (check/%.exp): Pass directory for GDB_PARALLEL.
(workers/%.worker, build-perf): New rule.
(GDB_PERFTEST_MODE): New variable.
(check-perf): Use it.
(clean): Clean up gdb.perf parallel build subdirs.
* lib/build-piece.exp: New file.
* lib/cache.exp (gdb_do_cache): Include $GDB_PARALLEL in path name.
* lib/gdb.exp (standard_output_file): Include $GDB_PARALLEL in path
name.
(standard_temp_file): Ditto.
(GDB_PARALLEL handling): Make outputs,temp,cache directories as subdirs
of $GDB_PARALLEL.