Add Float32x4List.fromList to runtime implementation and some tests

runtime/lib/typed_data.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // patch classes for Int8List ..... Float64List and ByteData implementations.
 
 patch class Int8List {
   /* patch */ factory Int8List(int length) {
     return new _Int8Array(length);
   }
@@ skipping 211 matching lines @@
                                        [int offsetInBytes = 0, int length]) {
     return new _Float64ArrayView(buffer, offsetInBytes, length);
   }
 }
 
 patch class Float32x4List {
   /* patch */ factory Float32x4List(int length) {
     return new _Float32x4Array(length);
   }
 
+  /* patch */ factory Float32x4List.fromList(List<Float32x4> elements) {
+    var result = new _Float32x4Array(elements.length);
+    for (int i = 0; i < elements.length; i++) {
+      result[i] = elements[i];
+    }
+    return result;
+  }
+
   /* patch */ factory Float32x4List.view(ByteBuffer buffer,
                                          [int offsetInBytes = 0, int length]) {
     return new _Float32x4ArrayView(buffer, offsetInBytes, length);
   }
 }
 
 
 patch class Float32x4 {
   /* patch */ factory Float32x4(double x, double y, double z, double w) {
     return new _Float32x4(x, y, z, w);
@@ skipping 3135 matching lines @@
     return value;
   }
   return object;
 }
 
 
 void _throwRangeError(int index, int length) {
   String message = "$index must be in the range [0..$length)";
   throw new RangeError(message);
 }