[class] Add tests for private fields with eval

Bug: v8:5368
Change-Id: I3119ce753737afd44a03d2c44348912a96da6c97
Reviewed-on: https://chromium-review.googlesource.com/952481
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51794}

test/mjsunit/harmony/private-fields.js

@@ -7,8 +7,6 @@
 
 "use strict";
 
-// TODO(gsathya): Missing tests:
-// (d) tests involving eval
 {
   class C {
     #a;
@@ -439,3 +437,42 @@
   c.b = () => c;
   assertEquals(1, c.getA(c));
 }
+
+{
+  class C {
+    #a = 1;
+    getA() { return eval('this.#a'); }
+  }
+
+  let c = new C;
+  assertEquals(1, c.getA());
+}
+
+{
+  var C;
+  eval('C = class {#a = 1;getA() { return eval(\'this.#a\'); }}');
+
+  let c = new C;
+  assertEquals(1, c.getA());
+}
+
+{
+  class C {
+    #a = 1;
+    getA() { return this.#a; }
+    setA() { eval('this.#a = 4'); }
+  }
+  let c = new C;
+  assertEquals(1, c.getA());
+  c.setA();
+  assertEquals(4, c.getA());
+}
+
+{
+  class C {
+    getA() { return eval('this.#a'); }
+  }
+
+  let c = new C;
+  assertThrows(() => c.getA(), SyntaxError);
+}