Disable the coroutines tests until Clang bumps __cpp_coroutines to reflect recent changes

llvm-svn: 303837
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: d791d4ea3c254a0112c1c67c7fd5054a39efa76b
1 file changed