Rollup merge of #101142 - nnethercote:improve-hir-stats, r=davidtwco

Improve HIR stats

#100398 improve the AST stats collection done by `-Zhir-stats`. This PR does the same for HIR stats collection.

r? `@davidtwco`

compiler/rustc_ast_lowering/src/lib.rs

@@ -1155,7 +1155,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     }
                     _ => {}
                 }
-                GenericArg::Type(self.lower_ty_direct(&ty, itctx))
+                GenericArg::Type(self.lower_ty(&ty, itctx))
             }
             ast::GenericArg::Const(ct) => GenericArg::Const(ConstArg {
                 value: self.lower_anon_const(&ct),