Upgrade clang to r450784e

To support NSAttributedString changes in Xcode 13.2
https://github.com/apple/llvm-project/commit/2de0a18a8949f0235fb3a08dcc55ff3aa7d969e7

Change-Id: Iaf07a0c271ea8654d5c7388ed84d36458d8fcfdf
3 files changed