Louis Dionne fd04fd9ac9 [libc++] Use CMake interface targets to setup benchmark flags
This is a re-application of da0592e4c8df which was reverted in
1454018dc1d9 because it was incompatible with older CMakes.
Instead, disable the benchmarks when CMake is too old to
support those idioms.

Differential Revision: https://reviews.llvm.org/D110285
2021-09-23 12:14:01 -04:00
..