[analyzer] [tests] Add an option for showing statistics after running tests.
[analyzer] [tests] Add an option for showing statistics after running tests.

Do not show statistics by default.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@338323 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang