Remove special casing of rustdoc in rustc_lint

This is no longer necessary now that rustdoc doesn't run
everybody_loops.

Author: jyn514

compiler/rustc_lint/src/early.rs

@@ -379,17 +379,9 @@ pub fn check_ast_crate<T: EarlyLintPass>(
     // All of the buffered lints should have been emitted at this point.
     // If not, that means that we somehow buffered a lint for a node id
     // that was not lint-checked (perhaps it doesn't exist?). This is a bug.
-    //
-    // Rustdoc runs everybody-loops before the early lints and removes
-    // function bodies, so it's totally possible for linted
-    // node ids to not exist (e.g., macros defined within functions for the
-    // unused_macro lint) anymore. So we only run this check
-    // when we're not in rustdoc mode. (see issue #47639)
-    if !sess.opts.actually_rustdoc {
-        for (_id, lints) in buffered.map {
-            for early_lint in lints {
-                sess.delay_span_bug(early_lint.span, "failed to process buffered lint here");
-            }
+    for (_id, lints) in buffered.map {
+        for early_lint in lints {
+            sess.delay_span_bug(early_lint.span, "failed to process buffered lint here");
         }
     }
 }