specs: expect portable wc command output format.
specs: expect portable wc command output format.

BSD and Mac OS X `wc` indent the output from `wc`.
* specs/posix_spec.yaml (popen_pipeline): Allow leading whitespace
in wc output.

Signed-off-by: Gary V. Vaughan <f9023000f29773649f3850298becb9544b5fd6a9@gnu.org>

snegovick/luaposix,ardje/luaposix,ardje/luaposix,rrthomas/luaposix,jimmyharris/luaposix,rrthomas/luaposix,snegovick/luaposix,jimmyharris/luaposix,luaposix/luaposix