Add test showing MinimizeExitPoints bug when AST is not normalized

PiperOrigin-RevId: 846832887

Author: lauraharker

test/com/google/javascript/jscomp/MinimizeExitPointsTest.java

@@ -322,6 +322,16 @@ public void testSwitchExitPoints1() {
         "switch (x) { case 1: if (x) { f();        } break; default: g();        }");
   }
 
+  @Test
+  public void testFoldBlockScopedVariables_bug() {
+    disableNormalize();
+    fold(
+        "function f() { if (x) {return;} else { let c = 1; } var c; return !!c; }",
+        // TODO: b/470408326 - fix this output.
+        // "Uncaught SyntaxError: Identifier 'c' has already been declared"
+        "function f() { if (x){} else { let c = 1; var c; return !!c; } }");
+  }
+
   @Test
   public void testFoldBlockScopedVariables() {
     // When moving block-scoped variable declarations into inner blocks, first convert them to