only run validation if code is actually transformed

Disables post-codegen validation if there were no React functions in the input.

compiler/forget/src/BackEnd/PostCodegenValidator.ts

@@ -20,6 +20,11 @@ export default {
 };
 
 export function run(lirProg: LIR.Prog, context: CompilerContext) {
+  // Only run validation if the input has React functions and was successfully
+  // transformed (no bailouts)
+  if (lirProg.funcs.size === 0 || context.bailouts.length !== 0) {
+    return;
+  }
   const postCodegenValidator = context.opts.postCodegenValidator;
   if (postCodegenValidator === null) {
     return;

compiler/forget/src/CompilerOptions.ts

@@ -151,7 +151,7 @@ export function createCompilerOptions(): CompilerOptions {
   return {
     outputKinds: [OutputKind.JS],
     flags: createCompilerFlags(),
-    stopPass: PassName.JSGen,
+    stopPass: PassName.Validator,
     optIn: false,
     logger: noopLogger,
     allowedCapitalizedUserFunctions: new Set(),