anchor.diff:  
     group('Expression compiler tests in conditional (else):', () {
       const source = r'''
  +      // @dart = 2.9
         int globalFunction() {
           int x = 1;
           var c = C(1, 2);
  
positive.code: 
    group('Expression compiler tests after conditionals:', () {
      const source = r'''
        int globalFunction() {
          int x = 1;
          var c = C(1, 2);
  
negative.code: 
    group('Expression compiler tests in loops:', () {
      const source = r'''
        // @dart = 2.9
        int globalFunction() {
          int x = 15;
          var c = C(1, 2);
  