ReleaseNotes: llvm-cov blurb; by Vedant Kumar
ReleaseNotes: llvm-cov blurb; by Vedant Kumar

git-svn-id: 27e84c199cfb3049f109a3001c965f4b97b0bded@295069 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm