Include anonymous functions into the list of methods in DebugInfo

[AnnaShaleva]

Current Behavior

Our compiler does not include anonymous functions into the methods list of debug info:

func PublicContractMethod() {
	var f = func() {
		runtime.Log("bla")
	}

	f()
	f()
}

See also thread under #3559 (comment).

Expected Behavior

Anonymous functions should be included into the methods list of debug info with some dynamic name that is not intersected with existing method names. A good example is given in #3559 (comment).

Possible Solution

Fix it.