clang tests were breaking, at least when compiling clang only, from an
installed llvm. Make the lit.cfg script deal with the case when we don't
have a host_triple available.
llvm-svn: 220152
Since these tests expect a working debugger, always compile them for the
host triple, assuming a working debugger is present.
This enables us to compile and run them, even when clang is, by default,
a cross-compiler (but can still target the host).
llvm-svn: 219992
Filipe Cabecinhas