Dependencies can become incompatible due to anonymous types

[MaryamZi]

Description:
Names of anonymous types in a module seem to change across compilations.

Seems like this can cause incompatibilities when using dependencies built on a different lang build

This is probably why we've often been seeing errors like "'lang.array:ArrayIterator' cannot be cast to 'lang.array:$anonType$_1'" and no such field errors for downstream builds.

Assume v1 is the older version which will add the cast from lang.array:ArrayIterator to lang.array:$anonType$_1' which is an object type. Assume the HTTP module is built on this version.

Assume v2 is the newer version where lang.array:$anonType$_1 represents a different anonymous type (may even be a record). Now if we use the HTTP module built on v1 with lang v2, the cast will fail.

Steps to reproduce:
Run the following sample on slp8.1

import ballerina/http;

public function main() {
    http:Cookie c1 = new("foo", "foo");
    http:Cookie c2 = new("bar", "bar");

    http:Request req = new;

    req.addCookies([c1, c2]);
}

ballerina run qwe.bal 

Compiling source
        qwe.bal

Running executable

error: {ballerina}TypeCastError {"message":"incompatible types: 'lang.array:ArrayIterator' cannot be cast to 'lang.array:$anonType$_1'"}
        at ballerina.http.1_0_4.Request:addCookies(http_request.bal:546)
           qwe:main(qwe.bal:8)

Affected Versions:
slalpha1