[compiler-rt] [compiler-rt][test][builtins] Check linker support for --start-group (PR #205610)

[Joel E. Denny via llvm-commits]

jdenny-ornl wrote:

> @jdenny-ornl Please apply the following change. Thanks.

I applied that diff on top of this PR.  As desired, the diff caused no change in the test results when targeting nvptx or amdgcn.

https://github.com/llvm/llvm-project/pull/205610