Parse the Swift calling convention in the managed type system

src/coreclr/tools/Common/JitInterface/CorInfoImpl.cs

@@ -1590,6 +1590,9 @@ private static CorInfoCallConvExtension ToCorInfoCallConvExtension(UnmanagedCall
                 case UnmanagedCallingConventions.Fastcall:
                     result = CorInfoCallConvExtension.Fastcall;
                     break;
+                case UnmanagedCallingConventions.Swift:
+                    result = CorInfoCallConvExtension.Swift;
+                    break;
                 default:
                     ThrowHelper.ThrowInvalidProgramException();
                     result = CorInfoCallConvExtension.Managed; // unreachable

src/coreclr/tools/Common/TypeSystem/Interop/UnmanagedCallingConventions.cs

@@ -40,7 +40,7 @@ public enum UnmanagedCallingConventions
         // Unmanaged            = 0x00000009, - this one is always translated to cdecl/stdcall
 
         // The ones higher than 0xF are defined by the type system
-        // There are no such calling conventions yet.
+        Swift                   = 0x00000010
     }
 
     public static class CallingConventionExtensions
@@ -181,6 +181,7 @@ private static UnmanagedCallingConventions AccumulateCallingConventions(Unmanage
                 "CallConvThiscall" => UnmanagedCallingConventions.Thiscall,
                 "CallConvSuppressGCTransition" => UnmanagedCallingConventions.IsSuppressGcTransition,
                 "CallConvMemberFunction" => UnmanagedCallingConventions.IsMemberFunction,
+                "CallConvSwift" => UnmanagedCallingConventions.Swift,
                 _ => null
             };