diff --git a/js/src/jit-test/tests/basic/shifted-elements1.js b/js/src/jit-test/tests/basic/shifted-elements1.js
new file mode 100644
index 000000000..ee001c5e3
--- /dev/null
+++ b/js/src/jit-test/tests/basic/shifted-elements1.js
@@ -0,0 +1,14 @@
+function f() {
+    var arr = [];
+    var iters = 1500;
+    for (var i = 0; i < iters; i++) {
+        arr.push(i);
+        if (i % 2 === 0)
+            assertEq(arr.shift(), i / 2);
+    }
+    assertEq(arr.length, iters / 2);
+    for (var i = iters / 2; i < iters; i++)
+        assertEq(arr.shift(), i);
+    assertEq(arr.length, 0);
+}
+f();
diff --git a/js/src/jit-test/tests/basic/shifted-elements2.js b/js/src/jit-test/tests/basic/shifted-elements2.js
new file mode 100644
index 000000000..f989db154
--- /dev/null
+++ b/js/src/jit-test/tests/basic/shifted-elements2.js
@@ -0,0 +1,22 @@
+// Always use the per-element barrier.
+gczeal(12);
+
+function f() {
+    var arr = [];
+    for (var i = 0; i < 1000; i++)
+        arr.push(i);
+    gc(); // Ensure arr is tenured.
+
+    // Now store a nursery object somewhere in the array, shift elements,
+    // trigger a GC, and check the post barrier kept the object alive.
+    for (var i = 0; i < 20; i++)
+        arr.shift();
+    for (var i = 0; i < 40; i++)
+        arr[900] = {x: i};
+    for (var i = 0; i < 10; i++)
+        arr.shift();
+    gc();
+
+    assertEq(arr[890].x, 39);
+}
+f();
diff --git a/js/src/jit-test/tests/basic/shifted-elements3.js b/js/src/jit-test/tests/basic/shifted-elements3.js
new file mode 100644
index 000000000..6bbe296fa
--- /dev/null
+++ b/js/src/jit-test/tests/basic/shifted-elements3.js
@@ -0,0 +1,23 @@
+// Always use the per-element barrier.
+gczeal(12);
+
+function f() {
+    var arr = [];
+    for (var i = 0; i < 1000; i++)
+        arr.push(i);
+    gc(); // Ensure arr is tenured.
+
+    for (var i = 0; i < 10; i++)
+        arr.shift();
+
+    // Add a nursery object, shift all elements, and trigger a GC to ensure
+    // the post barrier doesn't misbehave.
+    for (var j = 0; j < 40; j++)
+        arr[500] = {x: j};
+    while (arr.length > 0)
+        arr.shift();
+
+    gc();
+    return arr;
+}
+f();
diff --git a/js/src/jit-test/tests/basic/shifted-elements4.js b/js/src/jit-test/tests/basic/shifted-elements4.js
new file mode 100644
index 000000000..59bd83608
--- /dev/null
+++ b/js/src/jit-test/tests/basic/shifted-elements4.js
@@ -0,0 +1,11 @@
+function f() {
+    var arr = [];
+    for (var i = 0; i < 2; i++) {
+	for (var j = 0; j < 90000; j++)
+	    arr.push(j);
+	for (var j = 0; j < 90000; j++)
+	    assertEq(arr.shift(), j);
+	assertEq(arr.length, 0);
+    }
+}
+f();
diff --git a/js/src/jit-test/tests/basic/shifted-elements5.js b/js/src/jit-test/tests/basic/shifted-elements5.js
new file mode 100644
index 000000000..07e0bce5b
--- /dev/null
+++ b/js/src/jit-test/tests/basic/shifted-elements5.js
@@ -0,0 +1,39 @@
+function testFreeze() {
+    var arr = [];
+    for (var i = 0; i < 20; i++)
+        arr.push(i);
+    for (var i = 0; i < 10; i++)
+        arr.shift();
+    Object.freeze(arr);
+    assertEq(arr.length, 10);
+    arr[0] = -1;
+    assertEq(arr[0], 10);
+}
+testFreeze();
+testFreeze();
+
+function testCopyOnWrite() {
+    var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9];
+    for (var i = 0; i < 5; i++)
+        assertEq(arr.shift(), i + 1);
+    assertEq(arr.toString(), "6,7,8,9");
+}
+testCopyOnWrite();
+testCopyOnWrite();
+
+function testNonWritableLength() {
+    var arr = [];
+    for (var i = 0; i < 20; i++)
+        arr.push(i);
+    Object.defineProperty(arr, "length", {writable: false, value: arr.length});
+    var ex;
+    try {
+        arr.shift();
+    } catch(e) {
+        ex = e;
+    }
+    assertEq(ex instanceof TypeError, true);
+    assertEq(arr.length, 20);
+}
+testNonWritableLength();
+testNonWritableLength();
diff --git a/js/src/jit-test/tests/basic/shifted-elements6.js b/js/src/jit-test/tests/basic/shifted-elements6.js
new file mode 100644
index 000000000..671e49325
--- /dev/null
+++ b/js/src/jit-test/tests/basic/shifted-elements6.js
@@ -0,0 +1,17 @@
+// Test incremental GC slices and shifted elements.
+function f() {
+    var arr = [];
+    for (var i = 0; i < 1000; i++)
+        arr.push({x: i});
+    var arr2 = [];
+    for (var i = 0; i < 1000; i++) {
+        gcslice(900);
+        var o = arr.shift();
+        assertEq(o.x, i);
+        arr2.push(o);
+    }
+    gc();
+    for (var i = 0; i < 1000; i++)
+        assertEq(arr2[i].x, i);
+}
+f();
diff --git a/js/src/tests/ecma_7/String/shell.js b/js/src/tests/ecma_7/String/shell.js
new file mode 100644
index 000000000..e69de29bb
diff --git a/js/src/tests/ecma_7/String/string-pad-start-end.js b/js/src/tests/ecma_7/String/string-pad-start-end.js
new file mode 100644
index 000000000..d784c83e0
--- /dev/null
+++ b/js/src/tests/ecma_7/String/string-pad-start-end.js
@@ -0,0 +1,99 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+// `this` must be object coercable.
+
+for (let badThis of [null, undefined]) {
+    assertThrowsInstanceOf(() => {
+        String.prototype.padStart.call(badThis, 42, "oups");
+    }, TypeError);
+
+    assertThrowsInstanceOf(() => {
+        String.prototype.padEnd.call(badThis, 42, "oups");
+    }, TypeError);
+}
+
+let proxy = new Proxy({}, {
+get(t, name) {
+  if (name === Symbol.toPrimitive || name === "toString") return;
+  if (name === "valueOf") return () => 42;
+  throw "This should not be reachable";
+}
+});
+
+assertEq("42bloop", String.prototype.padEnd.call(proxy, 7, "bloopie"));
+
+// maxLength must convert to an integer
+
+assertEq("lame", "lame".padStart(0, "foo"));
+assertEq("lame", "lame".padStart(0.1119, "foo"));
+assertEq("lame", "lame".padStart(-0, "foo"));
+assertEq("lame", "lame".padStart(NaN, "foo"));
+assertEq("lame", "lame".padStart(-1, "foo"));
+assertEq("lame", "lame".padStart({toString: () => 0}, "foo"));
+
+assertEq("lame", "lame".padEnd(0, "foo"));
+assertEq("lame", "lame".padEnd(0.1119, "foo"));
+assertEq("lame", "lame".padEnd(-0, "foo"));
+assertEq("lame", "lame".padEnd(NaN, "foo"));
+assertEq("lame", "lame".padEnd(-1, "foo"));
+assertEq("lame", "lame".padEnd({toString: () => 0}, "foo"));
+
+assertThrowsInstanceOf(() => {
+    "lame".padStart(Symbol("9900"), 0);
+}, TypeError);
+
+assertThrowsInstanceOf(() => {
+    "lame".padEnd(Symbol("9900"), 0);
+}, TypeError);
+
+// The fill argument must be string coercable.
+
+assertEq("nulln.", ".".padStart(6, null));
+assertEq(".nulln", ".".padEnd(6, null));
+
+assertEq("[obje.", ".".padStart(6, {}));
+assertEq(".[obje", ".".padEnd(6, {}));
+
+assertEq("1,2,3.", ".".padStart(6, [1, 2, 3]));
+assertEq(".1,2,3", ".".padEnd(6, [1, 2, 3]));
+
+assertEq("aaaaa.", ".".padStart(6, {toString: () => "a"}));
+assertEq(".aaaaa", ".".padEnd(6, {toString: () => "a"}));
+
+// undefined is converted to " "
+
+assertEq("     .", ".".padStart(6, undefined));
+assertEq(".     ", ".".padEnd(6, undefined));
+
+assertEq("     .", ".".padStart(6));
+assertEq(".     ", ".".padEnd(6));
+
+// The empty string has no effect
+
+assertEq("Tilda", "Tilda".padStart(100000, ""));
+assertEq("Tilda", "Tilda".padEnd(100000, ""));
+
+assertEq("Tilda", "Tilda".padStart(100000, {toString: () => ""}));
+assertEq("Tilda", "Tilda".padEnd(100000, {toString: () => ""}));
+
+// Test repetition against a bruteforce implementation
+
+let filler = "space";
+let truncatedFiller = "";
+for (let i = 0; i < 2500; i++) {
+    truncatedFiller += filler[i % filler.length];
+    assertEq(truncatedFiller + "goto", "goto".padStart(5 + i, filler));
+    assertEq("goto" + truncatedFiller, "goto".padEnd(5 + i, filler));
+}
+
+// [Argument] Length
+
+assertEq(1, String.prototype.padStart.length)
+assertEq(1, String.prototype.padEnd.length)
+
+if (typeof reportCompare === "function")
+    reportCompare(true, true);
+