Added simple hack to reduce redundant warnings from the checker:
Added simple hack to reduce redundant warnings from the checker:

Cache the location of the error.  Don't emit the same
warning for the same error type that occurs at the same program
location but along a different path.
      


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@47727 91177308-0d34-0410-b5e6-96231b3b80d8

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