Add some initial memory tests

These can be executed using valgrind --tool=massif to get a rough idea of
memory behavior.  Valgrind massif using libc allocation primitives does
carry overhead that a proper pool allocator doesn't (they can be made
overhead free); but these numbers are still useful as guides.

tests/memory/test-function-expression-1.js

@@ -0,0 +1,8 @@
+function test() {
+    var arr = [];
+    while (arr.length < 1e5) {
+        arr.push(function () {});
+    }
+    print(arr.length + ' anonymous functions created');
+}
+test();

tests/memory/test-function-expression-2.js

@@ -0,0 +1,11 @@
+function test() {
+    var arr = [];
+    var fn;
+    while (arr.length < 1e4) {
+        fn = function () {};
+        fn.prototype = null;
+        arr.push(fn);
+    }
+    print(arr.length + ' anonymous functions created');
+}
+test();

tests/memory/test-plain-buffer-1.js

@@ -0,0 +1,8 @@
+function test() {
+    var arr = [];
+    while (arr.length < 1e5) {
+        arr.push(Uint8Array.allocPlain(256));
+    }
+    print(arr.length + ' plain buffers created');
+}
+test();

tests/memory/test-uint8array-1.js

@@ -0,0 +1,8 @@
+function test() {
+    var arr = [];
+    while (arr.length < 1e5) {
+        arr.push(new Uint8Array(256));
+    }
+    print(arr.length + ' Uint8Arrays created');
+}
+test();