Disable compilation of "Components" inside class methods

Minimal repro extracted from our internal codebase. Our inference mode sees that 
this arrow function is component-like and attempts to compile it, which then 
fails because the function accesses `this`  which we bailout on.

compiler/packages/babel-plugin-react-forget/src/Entrypoint/Program.ts

@@ -270,6 +270,20 @@ export function compileProgram(
   // Main traversal to compile with Forget
   program.traverse(
     {
+      ClassDeclaration(node: NodePath<t.ClassDeclaration>) {
+        // Don't visit functions defined inside classes, because they
+        // can reference `this` which is unsafe for compilation
+        node.skip();
+        return;
+      },
+
+      ClassExpression(node: NodePath<t.ClassExpression>) {
+        // Don't visit functions defined inside classes, because they
+        // can reference `this` which is unsafe for compilation
+        node.skip();
+        return;
+      },
+
       FunctionDeclaration(
         fn: NodePath<t.FunctionDeclaration>,
         pass: CompilerPass

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/class-component-with-render-helper.expect.md

@@ -0,0 +1,41 @@
+
+## Input
+
+```javascript
+// @compilationMode(infer)
+class Component {
+  _renderMessage = () => {
+    const Message = () => {
+      const message = this.state.message;
+      return <div>{message}</div>;
+    };
+    return <Message />;
+  };
+
+  render() {
+    return this._renderMessage();
+  }
+}
+
+```
+
+## Code
+
+```javascript
+// @compilationMode(infer)
+class Component {
+  _renderMessage = () => {
+    const Message = () => {
+      const message = this.state.message;
+      return <div>{message}</div>;
+    };
+    return <Message />;
+  };
+
+  render() {
+    return this._renderMessage();
+  }
+}
+
+```
+      

compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/class-component-with-render-helper.js

@@ -0,0 +1,14 @@
+// @compilationMode(infer)
+class Component {
+  _renderMessage = () => {
+    const Message = () => {
+      const message = this.state.message;
+      return <div>{message}</div>;
+    };
+    return <Message />;
+  };
+
+  render() {
+    return this._renderMessage();
+  }
+}

compiler/packages/sprout/src/SproutTodoFilter.ts

@@ -450,6 +450,7 @@ const skipFilter = new Set([
   "infer-function-expression-component",
   "infer-function-expression-React-memo-gating",
   "infer-skip-components-without-hooks-or-jsx",
+  "class-component-with-render-helper",
 ]);
 
 export default skipFilter;