Rename many DiagCtxt and EarlyDiagCtxt locals.

Author: nnethercote

clippy_lints/src/doc/needless_doctest_main.rs

@@ -45,10 +45,10 @@ pub fn check(
                 let fallback_bundle =
                     rustc_errors::fallback_fluent_bundle(rustc_driver::DEFAULT_LOCALE_RESOURCES.to_vec(), false);
                 let emitter = EmitterWriter::new(Box::new(io::sink()), fallback_bundle);
-                let handler = DiagCtxt::with_emitter(Box::new(emitter)).disable_warnings();
+                let dcx = DiagCtxt::with_emitter(Box::new(emitter)).disable_warnings();
                 #[expect(clippy::arc_with_non_send_sync)] // `Lrc` is expected by with_dcx
                 let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
-                let sess = ParseSess::with_dcx(handler, sm);
+                let sess = ParseSess::with_dcx(dcx, sm);
 
                 let mut parser = match maybe_new_parser_from_source_str(&sess, filename, code) {
                     Ok(p) => p,

src/driver.rs

@@ -174,9 +174,9 @@ const BUG_REPORT_URL: &str = "https://github.com/rust-lang/rust-clippy/issues/ne
 #[allow(clippy::too_many_lines)]
 #[allow(clippy::ignored_unit_patterns)]
 pub fn main() {
-    let handler = EarlyDiagCtxt::new(ErrorOutputType::default());
+    let early_dcx = EarlyDiagCtxt::new(ErrorOutputType::default());
 
-    rustc_driver::init_rustc_env_logger(&handler);
+    rustc_driver::init_rustc_env_logger(&early_dcx);
 
     let using_internal_features = rustc_driver::install_ice_hook(BUG_REPORT_URL, |handler| {
         // FIXME: this macro calls unwrap internally but is called in a panicking context!  It's not