Bug 1321444 - part 3 - add vs2015u3 to clang.manifest files; r=mshal

We need this for the Windows SDK et al.

browser/config/tooltool-manifests/win32/clang.manifest

@@ -23,6 +23,14 @@
 "size": 1179901
 },
 {
+"version": "Visual Studio 2015 Update 3 14.0.25425.01 / SDK 10.0.14393.0",
+"size": 326656969,
+"digest": "babc414ffc0457d27f5a1ed24a8e4873afbe2f1c1a4075469a27c005e1babc3b2a788f643f825efedff95b79686664c67ec4340ed535487168a3482e68559bc7",
+"algorithm": "sha512",
+"filename": "vs2015u3.zip",
+"unpack": true
+},
+{
 "version": "clang 4.0pre/r286542",
 "size": 206088429,
 "digest": "a6de709a5097d98084b6111e340f53cd8397736f783aa6f76c9d45bcb694d3983ab3b7aea7f96756fcc4ee44f7b0e57df5ebabbd59242cd51942742fe1769d9a",

browser/config/tooltool-manifests/win64/clang.manifest

@@ -24,6 +24,14 @@
 "size": 1179901
 },
 {
+"version": "Visual Studio 2015 Update 3 14.0.25425.01 / SDK 10.0.14393.0",
+"size": 326656969,
+"digest": "babc414ffc0457d27f5a1ed24a8e4873afbe2f1c1a4075469a27c005e1babc3b2a788f643f825efedff95b79686664c67ec4340ed535487168a3482e68559bc7",
+"algorithm": "sha512",
+"filename": "vs2015u3.zip",
+"unpack": true
+},
+{
 "version": "clang 4.0pre/r286542",
 "size": 210049255,
 "digest": "8da8c653ea1948c13aa152cf0b1b0fa94e9619c49006ec80cc625d33cbf2dafa3533764f38fc0213e469cc786a738e5099f0e39d52e30f9a711718e8a3124311",