Add to OptimizeArgumentsArrayTest

Documents some crashes on ES6 code and adds a few more cases.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=230648052

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

@@ -16,6 +16,7 @@
 
 package com.google.javascript.jscomp;
 
+import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -184,6 +185,11 @@ public void testDecimalArgumentIndex() {
     testSame("function f() { arguments[0.5]; }");
   }
 
+  @Test
+  public void testNegativeArgumentIndex() {
+    testSame("function badFunction() { arguments[-1]; }");
+  }
+
   @Test
   public void testArrowFunctions() {
 
@@ -284,7 +290,13 @@ public void testNestedFunctions() {
 
   @Test
   public void testNoOptimizationWhenArgumentIsUsedAsFunctionCall() {
-    testSame("function f() {arguments[0]()}");
+    testSame("function f() {arguments[0]()}"); // replacing the call would change `this`
+  }
+
+  @Test
+  public void testNoOptimizationWhenArgumentsReassigned() {
+    // replacing the post-assignment `arguments[0]` with a named parameter would be incorrect
+    testSame("function f() { arguments[0]; arguments = [3, 4, 5]; arguments[0]; }");
   }
 
   @Test
@@ -293,7 +305,27 @@ public void testUnusualArgumentsUsage() {
   }
 
   @Test
-  public void testNegativeIndexNoCrash() {
-    testSame("function badFunction() { arguments[-1]; }");
+  @Ignore
+  public void testUseArgumentsToAccessParamWithDefault() {
+    // TODO(b/123256727): fix this case. right now the pass crashes
+    test("function f(x = 0) { arguments[0]; }", "function f(x = 0) { x; }");
+  }
+
+  @Test
+  @Ignore
+  public void testUseArgumentsWithRestParam() {
+    // TODO(b/123256727): fix this case. right now the pass crashes
+    test("function f(x, ...rest) { arguments[1]; }", "function f(...rest) { rest[0]; }");
+
+    test("function f(x, ...rest) { arguments[2]; }", "function f(...rest) { rest[1]; }");
+  }
+
+  @Test
+  @Ignore
+  public void testUseArgumentsWithDestructuringParam() {
+    // TODO(b/123256727): fix this case. right now the pass crashes
+    test("function f([x, y]) { arguments[1]; }", "function f([x, y], p0) { p0; }");
+
+    testSame("function f([x, y]) { arguments[0]; }");
   }
 }