Clang doesn't like the -Wno-psabi argument that we want to pass to GCC. Since clang is detected as GCC via __GNUC__, use ax_cv_c_compiler_vendor.
Clang doesn't like the -Wno-psabi argument that we want to pass to GCC. Since clang is detected as GCC via __GNUC__, use ax_cv_c_compiler_vendor.