Swift 5.2

Swift 5.2 (2020/03/24)

apple/llvm-project @ c2133f2b0804
apple/swift @ 33150e32b4f
apple/swift-cmark @ bfa95d5
apple/swift-corelibs-libdispatch @ c992dac
apple/swift-corelibs-foundation @ 8d087153
apple/swift-corelibs-xctest @ b14c409