Test for var declarations in eval which conflict with let

test/mjsunit/harmony/block-eval-var-over-legacy-const.js

Index: test/mjsunit/harmony/block-eval-var-over-legacy-const.js
diff --git a/test/mjsunit/harmony/block-eval-var-over-legacy-const.js b/test/mjsunit/harmony/block-eval-var-over-legacy-const.js
new file mode 100644
index 0000000000000000000000000000000000000000..0eb84564333b43db99cfcd33b38b29317670c5ad
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+++ b/test/mjsunit/harmony/block-eval-var-over-legacy-const.js
@@ -0,0 +1,109 @@
+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-sloppy --harmony-sloppy-let --harmony-sloppy-function
+
+// Var-let conflict in a function throws, even if the var is in an eval
+
+let caught = false;
+
+// Throws at the top level of a function
+try {
+  (function() {
+    let x = 1;
+    eval('const x = 2');
+  })()
+} catch (e) {
+  caught = true;
+}
+assertTrue(caught);
+
+// If the eval is in its own block scope, throws
+caught = false;
+try {
+  (function() {
+    let y = 1;
+    { eval('const y = 2'); }
+  })()
+} catch (e) {
+  caught = true;
+}
+assertTrue(caught);
+
+// If the let is in its own block scope, with the eval, throws
+caught = false
+try {
+  (function() {
+    {
+      let x = 1;
+      eval('const x = 2');
+    }
+  })();
+} catch (e) {
+  caught = true;
+}
+assertTrue(caught);
+
+// Legal if the let is no longer visible
+caught = false
+try {
+  (function() {
+    {
+      let x = 1;
+    }
+    eval('const x = 2');
+  })();
+} catch (e) {
+  caught = true;
+}
+assertFalse(caught);
+
+// In global scope
+caught = false;
+try {
+  let z = 1;
+  eval('const z = 2');
+} catch (e) {
+  caught = true;
+}
+assertTrue(caught);
+
+// Let declarations beyond a function boundary don't conflict
+caught = false;
+try {
+  let a = 1;
+  (function() {
+    eval('const a');
+  })();
+} catch (e) {
+  caught = true;
+}
+assertFalse(caught);
+
+// var across with doesn't conflict
+caught = false;
+try {
+  (function() {
+    with ({x: 1}) {
+      eval("const x = 2;");
+    }
+  })();
+} catch (e) {
+  caught = true;
+}
+assertFalse(caught);
+
+// var can still conflict with let across a with
+caught = false;
+try {
+  (function() {
+    let x;
+    with ({x: 1}) {
+      eval("const x = 2;");
+    }
+  })();
+} catch (e) {
+  caught = true;
+}
+assertTrue(caught);