Better handling of duplicate symbols at the same address

[plafosse]

We can have multiple symbols at the same site. We need better handling in the UI for this. We should give some indication that there are multiple names for this somehow, this probably needs a lot of discussion to come to a good UI.

Additionally it would be great if we had a system very similar to "Call Type Override" but "Call Name Override" This would allow you at the call site specify on of the other symbols at the target.

[bpotchik]

Duplicate #4902

[utkonos]

Here is a use case for being able to show or pick one of multiple symbols at the same address. This is a list of hashes and function start addresses in a shellcode.

They're all referenced using a shellcode global register ebx. for calls to functions that are not at element zero in the list, the annotation for the calls in the shellcode look nice like this because I made a data symbol in those locations:

But that doesn't work when the first function in the list is called. Where that is called, I have to put a comment:

[fuzyll]

Not entirely sure how the issues related to this got in the state they are, but I'm choosing this as the winner. See #4849 for a related discussion as well.

Another use-case for this is with debug information, which may contain multiple symbols at the same address as well. For the case I'm familiar with, the compiler has optimized things and now multiple functions have the same implementation (or multiple variables share the same location). What I want here is something more similar to how we're handling unions: All of the names are potentially valid, and I would like to choose one to show at a particular location.

[zznop]

I also want to add that if a user changes a name of an exported function, it creates a new symbol at that address. Symbols view displays the newly created user-defined symbol (instead of the auto symbol) and that function no longer shows up in symbols view as being exported when you enable Show functions (exported) in the hamburger menu. And the pink text (that implies it is exported) also goes away.