Much work on try/catch statement.  WIP.
Much work on try/catch statement.  WIP.

Highlights include:

  Fix __cxa_begin_catch so it now returns a value.
  Added getUnwindResumeOrRethrowFn helper to build up calls to
  _Unwind_Resume_or_Rethrow.
  Broke out object copying code into CopyObject from EmitCXXThrowExpr.
  Built up another version of CopyObject that can copy from memory for
  use in the catch parameter code.
  RTTI generation for type matching for catch.
  Code to check for the type match for catch.
  Code to generate the catch parameter, WIP, need make sure references
  and pointers and copy ctors work.


git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@90205 91177308-0d34-0410-b5e6-96231b3b80d8

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