Add mapping data structures

[kevaundray]

Problem

A common strategy that wil be present in our SSA module is:

pub struct Data;

pub struct DataId

Where data gets stored in some Arena/Map and the DataId is the reference to get the Data from the Arena/Map.

Proposed solution

Implement a common data structure to abstract away this information. Cranelift uses PrimaryMap and SecondaryMap.

Alternatives considered

No response

Additional context

No response

Submission Checklist

• Once I hit submit, I will assign this issue to the Project Board with the appropriate tags.

[kevaundray]

One can look at the Cranelift datastructures to figure out what the API should look like. An alternative is to use petgraph (or atleast we can use it initially)

[guipublic]

For the record this is exactly the strategy we already have in the SSA module where data is stored in an Arena and referenced by its id being the index of the arena.