I think this is causing:
/home/espindola/llvm/llvm/utils/TableGen/SetTheory.h:58:1: warning:
struct 'Init' was previously
declared as a class [-Wmismatched-tags]
struct Init;
^
/home/espindola/llvm/llvm/utils/TableGen/Record.h:556:7: note: previous
use is here
class Init : public FastFoldingSetNode {