libselinux: improve performance with pcre matches am: 72806f3933 am: 0470684f9e am: 4d3b040b58

Original change: https://android-review.googlesource.com/c/platform/external/selinux/+/2411194

Change-Id: I73964710fcec1688fdb4fb1d1706428c4244d95d
Signed-off-by: Automerger Merge Worker <[email protected]>