libatomic-ops: upgrade 7.6.12 -> 7.6.14

libatomic-ops: upgrade 7.6.12 -> 7.6.14

License-Update:  Adjust/reformat content of LICENSING.txt
=========================================================
 "libatomic_ops_gpl.a" changed to "libatomic_ops_gpl.a file"
 "sysdeps" changed to "atomic_ops/sysdeps"
 "This applies only to test code, sample applications," changed to
 "This applies only to the test code"

Changelog:
==========
 Add note to README that AO malloc code has same license as AO stack
 Adjust/reformat content of LICENSING.txt
 Avoid AO_stack_t to cross CPU cache line boundary
 Do not assume 'ordered except earlier write' for UWP/arm64
 Do not name GCC intrinsics as C11 ones in ChangeLog and configure
 Eliminate '-pedantic is not option that controls warnings' GCC-6.3 message
 Ensure result of AO_test_and_set is always AO_TS_CLEAR or AO_TS_SET
 Fix 'AO_malloc redefinition' MS VC warning caused by attributes mismatch
 Fix 'use of undeclared SIG_BLOCK' Clang error if -std=c89 on Cygwin
 Fix AO_compare_and_swap_full asm code for clang on sparc
 Fix a typo in comment of AO_stack_push_explicit_aux_release
 Fix code indentation in main() of test_stack.c
 Refine AO_UNIPROCESSOR macro description in configure
 Remove outdated comment about unsupported Win64 in atomic_ops_stack.h
 Repeat black list check on CAS fail in stack_push_explicit_aux_release

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>