Use Span::is_dummy().

Author: khuey

compiler/rustc_codegen_llvm/src/debuginfo/mod.rs

@@ -570,7 +570,7 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> {
         inlined_at: Option<&'ll DILocation>,
         span: Span,
     ) -> &'ll DILocation {
-        let (line, col) = if span == DUMMY_SP && !self.sess().target.is_like_msvc {
+        let (line, col) = if span.is_dummy() && !self.sess().target.is_like_msvc {
             (0, 0)
         } else {
             let DebugLoc { line, col, .. } = self.lookup_debug_loc(span.lo());