[TableGen] Prevent invalid code generation when emitting AssemblerPredicate conditions.
Summary:
The loop which emits AssemblerPredicate conditions also links them together by emitting a '&&'.
If the 1st predicate is not an AssemblerPredicate, while the 2nd one is, nothing gets emitted for the 1st one, but we still emit the '&&' because of the 2nd predicate.
This generated code looks like "( && Cond2)" and is invalid.
Reviewers: dsanders
Reviewed By: dsanders
Subscribers: dsanders, llvm-commits
Differential Revision: http://reviews.llvm.org/D8294
llvm-svn: 234312