feat: account for rule creation time in performance reports

docs/src/developer-guide/working-with-rules.md

@@ -732,7 +732,7 @@ Performance budget ok:  1443.736547ms (limit: 3409.090909090909ms)
 
 ### Per-rule Performance
 
-ESLint has a built-in method to track performance of individual rules. Setting the `TIMING` environment variable will trigger the display, upon linting completion, of the ten longest-running rules, along with their individual running time and relative performance impact as a percentage of total rule processing time.
+ESLint has a built-in method to track performance of individual rules. Setting the `TIMING` environment variable will trigger the display, upon linting completion, of the ten longest-running rules, along with their individual running time (rule creation + rule execution) and relative performance impact as a percentage of total rule processing time (rule creation + rule execution).
 
 ```bash
 $ TIMING=1 eslint lib

lib/linter/linter.js

@@ -1101,7 +1101,7 @@ function runRules(sourceCode, configuredRules, ruleMapper, parserName, languageO
             )
         );
 
-        const ruleListeners = createRuleListeners(rule, ruleContext);
+        const ruleListeners = timing.enabled ? timing.time(ruleId, createRuleListeners)(rule, ruleContext) : createRuleListeners(rule, ruleContext);
 
         /**
          * Include `ruleId` in error logs

lib/linter/timing.js

@@ -138,10 +138,11 @@ module.exports = (function() {
 
         return function(...args) {
             let t = process.hrtime();
+            const result = fn(...args);
 
-            fn(...args);
             t = process.hrtime(t);
             data[key] += t[0] * 1e3 + t[1] / 1e6;
+            return result;
         };
     }