nptl: Consolidate async cancel enable/disable implementation in libc

Previously, the source file nptl/cancellation.c was compiled multiple
times, for libc, libpthread, librt.  This commit switches to a single
implementation, with new __pthread_enable_asynccancel@@GLIBC_PRIVATE,
__pthread_disable_asynccancel@@GLIBC_PRIVATE exports.

The almost-unused CANCEL_ASYNC and CANCEL_RESET macros are replaced
by LIBC_CANCEL_ASYNC and LIBC_CANCEL_ASYNC macros.  They call the
__pthread_* functions unconditionally now.  The macros are still
needed because shared code uses them; Hurd has different definitions.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/nptl/Versions b/nptl/Versions
index ce09c73727..e845cbf804 100644
--- a/nptl/Versions
+++ b/nptl/Versions
@@ -281,6 +281,8 @@ libc {
     __pthread_cleanup_push;
     __pthread_cleanup_upto;
     __pthread_current_priority;
+    __pthread_disable_asynccancel;
+    __pthread_enable_asynccancel;
     __pthread_force_elision;
     __pthread_getattr_default_np;
     __pthread_keys;