Support detecting .NET Core 1.0 and 1.1

Author: ds5678

ICSharpCode.Decompiler/Metadata/DotNetCorePathFinderExtensions.cs

@@ -97,28 +97,24 @@ public static string DetectTargetFrameworkId(this MetadataReader metadata, strin
 							return $".NETStandard,Version=v{version}";
 						case "System.Runtime":
 							// System.Runtime.dll uses the following scheme:
+							// 4.1.0 => .NET Core 1.0
+							// 4.1.1 => .NET Core 1.1
 							// 4.2.0 => .NET Core 2.0
 							// 4.2.1 => .NET Core 2.1 / 3.0
 							// 4.2.2 => .NET Core 3.1
 							// 5.0.0+ => .NET 5+
-							if (r.Version >= new Version(4, 2, 0))
+							version = (r.Version.Major, r.Version.Minor, r.Version.Build) switch
+							{
+								(4, 1, 0) => "1.0",
+								(4, 1, 1) => "1.1",
+								(4, 2, 0) => "2.0",
+								(4, 2, 1) => "3.0",
+								(4, 2, 2) => "3.1",
+								(>= 5, _, _) => r.Version.ToString(2),
+								_ => null
+							};
+							if (version != null)
 							{
-								if (r.Version.Major >= 5)
-								{
-									version = r.Version.ToString(2);
-								}
-								else if (r.Version.Major == 4 && r.Version.Minor == 2)
-								{
-									version = r.Version.Build switch {
-										<= 0 => "2.0",
-										1 => "3.0",
-										_ => "3.1"
-									};
-								}
-								else
-								{
-									version = "2.0";
-								}
 								return $".NETCoreApp,Version=v{version}";
 							}
 							else