Merge "sigqueue/pthread_sigqueue: cleanup." into main am: 18c76a005c

Original change: https://android-review.googlesource.com/c/platform/bionic/+/3206750

Change-Id: Id48a9145e46f2d38229ab8170851f30fc05b156d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>