Should we update ReturnParameter when updating ReturnType?

[CreateAndInject]

dnlib/src/DotNet/MethodDef.cs

Lines 493 to 500 in 71946df

	public TypeSig ReturnType {
	get => MethodSig?.RetType;
	set {
	var ms = MethodSig;
	if (ms is not null)
	ms.RetType = value;
	}
	}

		public TypeSig ReturnType {
			get => MethodSig?.RetType;
			set {
				var ms = MethodSig;
				if (ms is not null)
					ms.RetType = value;
				parameterList.ReturnParameter.Type = value;
			}
		}

[wtfsck]

Makes sense.

[wtfsck]

Fixed by #549