Created initial implementation of "BuildSerializer", and ASTConsumer which serializes ASTs to a common output directory.  This ASTConsumer is invoked using a combination of "-o" and "-serialize" from the driver.
Created initial implementation of "BuildSerializer", and ASTConsumer
which serializes ASTs to a common output directory.  This ASTConsumer
is invoked using a combination of "-o" and "-serialize" from the driver.


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@45241 91177308-0d34-0410-b5e6-96231b3b80d8

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