NSPR 4.9.6 has the following bug fixes:
* Bug 782214: Auto detect Android API version for x86.
* Bug 807883: Add the PL_SizeOfArenaPoolExcludingPool function.
* Bug 812085: Initialize Windows CRITICAL_SECTIONs without debug info
and with nonzero spin count.
* Bug 827271: Add support for Aarch64 (64-Bit ARM).
* Bug 841651: PR_SetThreadPriority doesn't do anything when using Bionic.
Bump minor for PL_SizeOfArenaPoolExcludingPool addition.
f3aa48856f