perf: Use === or Set.has instead of array.indexOf for keyword checks

packages/babel-parser/src/parser/base.js

@@ -1,7 +1,7 @@
 // @flow
 
 import type { Options } from "../options";
-import { reservedWords } from "../util/identifier";
+import { isES2015ReservedWord } from "../util/identifier";
 
 import type State from "../tokenizer/state";
 import type { PluginsMap } from "./index";
@@ -21,7 +21,7 @@ export default class BaseParser {
     if (word === "await") {
       return this.inModule;
     } else {
-      return reservedWords[6](word);
+      return isES2015ReservedWord(word);
     }
   }
 

packages/babel-parser/src/parser/expression.js

@@ -21,7 +21,10 @@
 import { types as tt, type TokenType } from "../tokenizer/types";
 import * as N from "../types";
 import LValParser from "./lval";
-import { reservedWords } from "../util/identifier";
+import {
+  isStrictReservedWord,
+  isStrictBindReservedWord,
+} from "../util/identifier";
 import type { Pos, Position } from "../util/location";
 import * as charCodes from "charcodes";
 
@@ -1997,8 +2000,8 @@ export default class ExpressionParser extends LValParser {
   ): void {
     if (
       this.state.strict &&
-      (reservedWords.strict(word) ||
-        (isBinding && reservedWords.strictBind(word)))
+      (isStrictReservedWord(word) ||
+        (isBinding && isStrictBindReservedWord(word)))
     ) {
       this.raise(startLoc, word + " is a reserved word in strict mode");
     }