I missed this when fixing an earlier bug with emitting custom attributes for parameters.
This patch emits attributes for constructors too.
Also, custom attributes on the return type of a method are not emitted. Although apparently there is a bug in .NET 1.1's system.reflection.emit preventing this from working anyway (DefineParameter cannot be called with an index of 0, which specifies the return type). This prevents using things like wsdl generated wrapper classes (using the google api for example).