fix CI

Author: bobzhang

jscomp/build_tests/scoped_ppx/input.js

@@ -2,7 +2,7 @@ var cp = require("child_process");
 var assert = require('assert')
 cp.execSync(`bsb`, { cwd: __dirname, stdio: [0, 1, 2], encoding: "utf8" });
 
-var output = cp.execSync(`bsb -- -t commands src/hello.mlast`, {
+var output = cp.execSync(`bsb -- -t commands src/hello.ast`, {
   cwd: __dirname,
   encoding: "utf8"
 });