Workaround VS 2015 support since Clang cannot handle it yet.

Errors:

C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\xtr1common(227,22): error: use of undeclared identifier 'char16_t'
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\xtr1common(233,22): error: use of undeclared identifier 'char32_t'
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\xstddef(408,14):error: use of undeclared identifier 'char16_t'
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\include\xstddef(414,14):error: use of undeclared identifier 'char32_t'
C:\Program Files (x86)\Windows Kits\8.1\include\um\winnt.h(938,2): error: Must define a target architecture.
C:\Program Files (x86)\Windows Kits\8.1\include\um\oaidl.h(473,31): error: cannot combine with previous 'type-name' declaration specifier

src/Core/Toolchains/MSVCToolchain.cs

@@ -106,6 +106,11 @@ namespace CppSharp
             if (vsSdks.Count == 0)
                 throw new Exception("Could not find a valid Visual Studio toolchain");
 
+            // Clang cannot deal yet with VS 2015, so remove it from SDKs.
+            if (vsVersion == VisualStudioVersion.Latest)
+                vsSdks.Remove(vsSdks.Find(version =>
+                    (int) version.Version == GetVisualStudioVersion(vsVersion)));
+
             var vsSdk = (vsVersion == VisualStudioVersion.Latest)
                 ? vsSdks.Last()
                 : vsSdks.Find(version =>