[BUG]: Some tests do not support C++11

[ahendriksen]

Is this a duplicate?

• I confirmed there appear to be no duplicate issues for this bug and that I agree to the Code of Conduct

Type of Bug

Something else

Component

libcu++

Describe the bug

Some recently added tests fail when run with -std=c++11.

How to Reproduce

lit build/local/libcudacxx/test/cuda -vv   --param=std=c++11 --filter='.*barrier.*'
lit build/local/libcudacxx/test/cuda -vv   --param=std=c++11 --filter='.*cp_async.*'
lit build/local/libcudacxx/test/cuda -vv   --param=std=c++11 --filter='.*memcpy_async.*'

Expected behavior

Tests do not fail or are skipped when the standard version is not supported.

Reproduction link

No response

Operating System

No response

nvidia-smi output

No response

NVCC version

No response