Merge remote-tracking branch 'aosp/upstream-master' into up-shaderc2

Refresh with content from github.com/google/re2
commit 79ef3b2d31f06493f687ef9e947d9632bad54b9b
date 2019-02-13

Change-Id: I4139f29d632e41722992309e96aca4f29c799c87