Slightly improve Visual Studio visualization of clang::Expr
Slightly improve Visual Studio visualization of clang::Expr

Now it gives the StmtClass of the Expr as well as the type. It's still
a long way from full visualization of expressions, but I have found
that having the class really helps when debugging, so definitely
worth submitting.


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@271866 91177308-0d34-0410-b5e6-96231b3b80d8

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