Fix #1267: GacInterop: Ignore null values in GetNextAssembly loop.

ILSpy/GacInterop.cs

@@ -40,6 +40,7 @@ namespace ICSharpCode.ILSpy
 			
 			Fusion.CreateAssemblyEnum(out assemblyEnum, null, null, 2, 0);
 			while (assemblyEnum.GetNextAssembly(out applicationContext, out assemblyName, 0) == 0) {
+				if (assemblyName == null) continue;
 				uint nChars = 0;
 				assemblyName.GetDisplayName(null, ref nChars, 0);