This patch removes the SymbolFileSymtab support

for reporting class types from Objective-C runtime
class symbols.  Instead, LLDB now queries the 
Objective-C runtime for class types.

We have also added a (minimal) Objective-C runtime
type vendor for Objective-C runtime version 1, to 
prevent regressions when calling class methods in
the V1 runtime.

Other components of this fix include:

- We search the Objective-C runtime in a few more
  places.

- We enable enumeration of all members of
  Objective-C classes, which Clang does in certain
  circumstances.

- SBTarget::FindFirstType and SBTarget::FindTypes
  now query the Objective-C runtime as needed.

- I fixed several test cases.

<rdar://problem/12885034>

llvm-svn: 170601