<rdar://problem/11146929>

Enabling support for the wchar_t type.
Without the proper language option setup, clang's ASTContexts will be configured to have wchar_t == int
This patch enables the correct options to make sure that we report wchar_t as itself
Added a test case to make sure we do not regress 



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@172038 91177308-0d34-0410-b5e6-96231b3b80d8