Replace infallible `name_or_empty` methods with fallible `name` methods.

I'm removing empty identifiers everywhere, because in practice they
always mean "no identifier" rather than "empty identifier". (An empty
identifier is impossible.) It's better to use `Option` to mean "no
identifier" because you then can't forget about the "no identifier"
possibility.

Some specifics:
- When testing an attribute for a single name, the commit uses the
  `has_name` method.
- When testing an attribute for multiple names, the commit uses the new
  `has_any_name` method.
- When using `match` on an attribute, the match arms now have `Some` on
  them.

In the tests, we now avoid printing empty identifiers by not printing
the identifier in the `error:` line at all, instead letting the carets
point out the problem.

1 files changed, 11 insertions, 11 deletions

diff --git a/compiler/rustc_passes/src/debugger_visualizer.rs b/compiler/rustc_passes/src/debugger_visualizer.rs
index 062d56a79a0..7a7a8175e55 100644
--- a/compiler/rustc_passes/src/debugger_visualizer.rs
+++ b/compiler/rustc_passes/src/debugger_visualizer.rs
@@ -28,17 +28,17 @@ impl DebuggerVisualizerCollector<'_> {
                 return;
             };
 
-            let (visualizer_type, visualizer_path) =
-                match (meta_item.name_or_empty(), meta_item.value_str()) {
-                    (sym::natvis_file, Some(value)) => (DebuggerVisualizerType::Natvis, value),
-                    (sym::gdb_script_file, Some(value)) => {
-                        (DebuggerVisualizerType::GdbPrettyPrinter, value)
-                    }
-                    (_, _) => {
-                        self.sess.dcx().emit_err(DebugVisualizerInvalid { span: meta_item.span });
-                        return;
-                    }
-                };
+            let (visualizer_type, visualizer_path) = match (meta_item.name(), meta_item.value_str())
+            {
+                (Some(sym::natvis_file), Some(value)) => (DebuggerVisualizerType::Natvis, value),
+                (Some(sym::gdb_script_file), Some(value)) => {
+                    (DebuggerVisualizerType::GdbPrettyPrinter, value)
+                }
+                (_, _) => {
+                    self.sess.dcx().emit_err(DebugVisualizerInvalid { span: meta_item.span });
+                    return;
+                }
+            };
 
             let file = match resolve_path(&self.sess, visualizer_path.as_str(), attr.span) {
                 Ok(file) => file,