Implement concurrent execution of print_debug_* functions during handling
of -w, --debug-dump using libthread.a.
A new `-C, --concurrency=NUM` command line option controls the maximum
number of threads that may be used. This value defaults to the number of CPUs.
Job output is buffered and printed
Calls to the gettext _() macro in hotpaths cause many runtime lookups
of the same translation strings. This patch introduces macro __()
which caches the result of _() at each call site where __() is used.
When a cached translation string is used as the format string for
fprintf, the compiler migh
Add new internal static library libthread.a that provides infrastructure
for eu-* tools to run functions concurrently using pthreads.
threadlib.c manages per-job threads as well as per-job buffers for stdout
output. Output for each job is printed to stdout in the order that the
jobs were added to
