fix clang not being detected as clang #29

Job	Run time
MSRV (ubuntu-latest)	22s
MSRV (windows-latest)	37s
Clippy	13s
Test build-std (aarch64-tvos)	4m 37s
Test CUDA support	50s
Test build-std (aarch64-tvos-sim)	2m 17s
Rustfmt	12s
Test build-std (x86_64-tvos)	2m 32s
Test (stable)	33s
Test (beta)	37s
Test (nightly)	27s
Test (linux32)	1m 28s
Test (macos)	3m 30s
Test (aarch64-macos)	41s
Test (aarch64-ios)	1m 24s
Test (win32)	1m 23s
Test (win64)	1m 34s
Test (mingw32)	1m 23s
Test (mingw64)	1m 20s
Test (windows-2019)	1m 19s
Test (windows-aarch64, windows-latest, stable, aarch64-pc-windows-msvc, --no-run)	2m 16s
Test (windows-clang, windows-2019, stable, x86_64-pc-windows-msvc, clang, clang++)	3m 26s
Test (windows-clang-cl, windows-2019, stable, x86_64-pc-windows-msvc, clang-cl, clang-cl)	1m 59s
	35m 0s

Provide feedback