perf: Move input to state and precalculate length

This also fixes a bug with async functions

packages/babel-parser/src/tokenizer/state.js

@@ -24,6 +24,7 @@ type TopicContextState = {
 export default class State {
   strict: boolean;
   input: string;
+  length: number;
 
   curLine: number;
 
@@ -37,6 +38,7 @@ export default class State {
       options.strictMode === false ? false : options.sourceType === "module";
 
     this.input = input;
+    this.length = input.length;
 
     this.curLine = options.startLine;
     this.startLoc = this.endLoc = this.curPosition();