ISO_Fortran_binding.h was only added to in gcc 10.0. Flang should be buildable with older versions. Remove the test until a safe way to check that the compiler can run the test (that it is clang from the build for instance). Fix bots failure https://lab.llvm.org/buildbot/#/builders/181/builds/24526 Also in: https://lab.llvm.org/buildbot/#/builders/160 https://lab.llvm.org/buildbot/#/builders/268 https://lab.llvm.org/buildbot/#/builders/181