nptl: Add test cases for ISO C11 threads

nptl: Add test cases for ISO C11 threads

This patch adds to testsuite new test cases to test all new introduced
C11 threads functions, types and macros are tested.

Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu,
arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu,
microblaze-linux-gnu [1], mips{64}-linux-gnu, nios2-linux-gnu,
powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu,
and x86_64-linux-gnu).

Also ran a full check on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
arm-linux-gnueabhf, and powerpc64le-linux-gnu.

	Adhemerval Zanella  <adhemerval.zanella@linaro.org>
	Juan Manuel Torres Palma  <jmtorrespalma@gmail.com>

	[BZ #14092]
	* nptl/Makefile (tests): Add new test files.
	* nptl/tst-call-once.c : New file. Tests C11 functions and types.
	* nptl/tst-cnd-basic.c: Likewise.
	* nptl/tst-cnd-broadcast.c: Likewise.
	* nptl/tst-cnd-timedwait.c: Likewise.
	* nptl/tst-mtx-basic.c: Likewise.
	* nptl/tst-mtx-recursive.c: Likewise.
	* nptl/tst-mtx-timedlock.c: Likewise.
	* nptl/tst-mtx-trylock.c: Likewise.
	* nptl/tst-thrd-basic.c: Likewise.
	* nptl/tst-thrd-detach.c: Likewise.
	* nptl/tst-thrd-sleep.c: Likewise.
	* nptl/tst-tss-basic.c: Likewise.