[XRay] [compiler-rt] Mark arg1 logging test as failing on !x86_64.

Summary:
rL297000 and rL297003 implemented arg1 logging on amd64 and made
other architectures build.  We need to blacklist the new test as well.

Reviewers: dberris, timshen

Reviewed By: dberris

Subscribers: sdardis, llvm-commits

Differential Revision: https://reviews.llvm.org/D30635

llvm-svn: 297238