liburcu: upgrade 0.15.1 -> 0.15.2

liburcu: upgrade 0.15.1 -> 0.15.2

Changelog:
==========
 * fix: __atomic_always_lock_free() not a constant expression on g++ < 5.1
 * fix: urcu assert fallback for pre-C11 builds
 * doc: update uatomic-api for static assert
 * Add uatomic size static assert for 's390'
 * Add uatomic size static assert for 'sparc64'
 * Add uatomic size static assert for 'ppc'
 * Add uatomic size static assert for 'x86'
 * Add uatomic size static assert for 'generic'
 * Add uatomic size static assert
 * Use UATOMIC_HAS_ATOMIC_INT/LLONG in generic implementation
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for x86
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for tile
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for sparc64
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for s390
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for riscv
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for ppc
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for nios2
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for mips
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for m68k
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for loongarch
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for ia64
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for hppa
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for 'gcc' arch
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for arm
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for alpha
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for aarch64
 * Add UATOMIC_HAS_ATOMIC_INT/LLONG for atomic builtins
 * Add builtin atomics size static asserts
 * cleanup: use URCU_GCC_VERSION from compiler.h
 * fix: atomic builtins defines for type support
 * Move back CMM_LOAD/STORE_SHARED to volatile access
 * Add cmm_annotate_mem_acquire() to URCU_DEREFERENCE_USE_VOLATILE rcu_dereference
 * Use uatomic_load CMM_RELAXED in URCU_DEREFERENCE_USE_VOLATILE
 * Fix: Re-introduce URCU_DEREFERENCE_USE_VOLATILE read barrier depends for alpha
 * Tree-wide: Rename to uatomic_load/uatomic_store
 * src: Use __*__ for attribute names
 * API: Use __*__ for attribute names
 * Fix Changelog 0.15.1 date

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>