ck_tflock: Initial check-in of reference implementation.
regressions/ck_tflock: Remove rwlock reference.
ck_swlock: A single writer rwlock.

This lock is copy-safe when the latch operations are used.

Simplified write side operations lead to lower latencies than ck_rwlock
for single writer workloads.
ck_swlock: First round fixes for ck_swlock.

- Add necessary memory barriers.
- Style conformance.
ck_swlock: Switch to TATAS style loop for latch operations.
ck_swlock: Fix-up TATAS loop.
ck_swlock: Fix Copyright ordering.
ck_swlock: Whitespace change.
regressions: Remove optimization flags from ck_swlock.
regressions/ck_swlock: Fix-up style and Copyright.
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.
ck_swlock: We shouldn't decrement n_readers when
ck_swlock_read_latchlocks observers a writer if the unlatch
operation sets n_readers to 0.

The unlatch operation now just unsets the latch bit, we can safely
decrement n_readers in ck_swlock_read_latchlocks().

+ Fixes to validation tests & ELIDE coverage.
Merge remote-tracking branch 'jsridhar-dev/ck_swlock' into ck_swlock

Conflicts:
	include/ck_swlock.h
	regressions/ck_swlock/validate/validate.c
ck_swlock: Fix makefile
ck_swlock: Decrement n_readers in TATAS style loop.
ck_swlock: Validation for normal write lock
ck_swlock: Need barrier
ck_swlock: Convert ELIDE tests to single writer