Do not use relative RPATHs on macOS with ICC/GCC

* Currently, absolute rpaths on macOS are only used
  with Clang, which breaks Meson builds when using
  ICC or GCC from Homebrew or MacPorts.

mesonbuild/compilers/c.py

@@ -121,7 +121,8 @@ class CCompiler(Compiler):
     # The default behavior is this, override in MSVC
     @functools.lru_cache(maxsize=None)
     def build_rpath_args(self, build_dir, from_dir, rpath_paths, build_rpath, install_rpath):
-        if self.id == 'clang' and self.compiler_type == CompilerType.CLANG_OSX:
+        if getattr(self, 'compiler_type', False) and self.compiler_type.is_osx_compiler:
+            # Clang, GCC and ICC on macOS all use the same rpath arguments
             return self.build_osx_rpath_args(build_dir, rpath_paths, build_rpath)
         return self.build_unix_rpath_args(build_dir, from_dir, rpath_paths, build_rpath, install_rpath)