ck_tflock: Initial check-in of reference implementation.
regressions/ck_tflock: Remove rwlock reference.
ck_cc: new bitwise ops

GCC and compatible compilers support ffs/ctz/clz/popcount. Expose that
in ck_cc and default to slow but portable software emulation.
ck_bitmap: more bulk operations, less space, more tests

* new bulk rmw: intersection, intersection_negate (with complement),
* new bulk reads: empty, full, count, count_intersect

* ck_bitmap_iterator fixes: avoid out of bounds read on empty bitmaps,
  and ck_bitmap_next is marginally faster on sparse bitmaps .

* less space: the bitmap itself is an array of unsigned int, which
  eliminates alignment padding between the n_bit field and the bitmap.

* more unit tests.
gitignore: add regressions/ck_spinlock/validate/ck_hclh

 and sort regressions/ noise alphabetically.
Merge pull request #4 from pkhuong/bitmapery
ck_rwlock: Remove debug optimization level.
regressions: Fix function declaration for ck_bitmap test.
ck_swlock: make ck_swlock_recursive_write_unlatch() wait-free.
Merge remote-tracking branch 'upstream/master' into ck_swlock

Conflicts:
	.gitignore
tflock: Task-fair reader-writer locks reference implementation.
regressions: Add ck_tflock tests to top-level Makefile.
regressions: Add ck_tflock build targets.
ck_tflock: Remove extraneous newline.
regressions: Add ck_tflock_init coverage.
ck_pflock: Migrate initializer to use compiler barrier.
*lock: Simply use compiler barrier on initialization.
*lock: Simplify initialization semantics.

Compiler barrier used for backwards compatibility.
ck_swlock: Use single word for lock bits
ck_swlock: Rename lock field