[NewPM] Run ubsan-coroutines test under the legacy pass manager only

The passes that lower the llvm.coro.* instrinsics have not yet been ported,
so only run under the legacy PM for now.

See https://bugs.llvm.org/show_bug.cgi?id=42867

Differential Revision: https://reviews.llvm.org/D66493

llvm-svn: 369442