Add an expectedFailure test for type finding.

When two .c files define a type of the same name, lldb
just picks one and uses it regardless of context.  That is
not correct.  When stopped in a frame in one of the .c files
that define this type, it should use that local definition.

This commit just adds a test that checks for the correct
behavior.  It is currently xfailed.

llvm-svn: 366507