[Bug target/66523] the new clang-based assembler in Xcode 7 on 10.11 fails on libobjc/NXConstStr.m

[howarth.at.gcc at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66523

--- Comment #5 from Jack Howarth <howarth.at.gcc at gmail dot com> ---
This is the last remaining issue with building gcc trunk using the clang-based
assembler in Xcode 7. Should we check in Iain's proposed fix for now as a
stop-gap fix>