fix: do not push new token context when function is following dot/questionDot (#11388)

* fix: do not push new token context when function is following dot/questionDot

* more cautiously poping context

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

@@ -2125,17 +2125,15 @@ export default class ExpressionParser extends LValParser {
     } else if (this.state.type.keyword) {
       name = this.state.type.keyword;
 
-      // `class` and `function` keywords push new context into this.context.
+      // `class` and `function` keywords push function-type token context into this.context.
       // But there is no chance to pop the context if the keyword is consumed
       // as an identifier such as a property name.
-      // If the previous token is a dot, this does not apply because the
-      // context-managing code already ignored the keyword
+      const context = this.state.context;
       if (
         (name === "class" || name === "function") &&
-        (this.state.lastTokEnd !== this.state.lastTokStart + 1 ||
-          this.input.charCodeAt(this.state.lastTokStart) !== charCodes.dot)
+        context[context.length - 1].token === "function"
       ) {
-        this.state.context.pop();
+        context.pop();
       }
     } else {
       throw this.unexpected();

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

@@ -101,7 +101,10 @@ tt.incDec.updateContext = function() {
 };
 
 tt._function.updateContext = tt._class.updateContext = function(prevType) {
-  if (
+  if (prevType === tt.dot || prevType === tt.questionDot) {
+    // when function/class follows dot/questionDot, it is part of
+    // (optional)MemberExpression, then we don't need to push new token context
+  } else if (
     prevType.beforeExpr &&
     prevType !== tt.semi &&
     prevType !== tt._else &&