The first part (e.g. register_bignumeral_interpretation) deals only with
the interp/uninterp closures. It should typically be done as a side
effect during a syntax plugin loading. No prim notation are active yet
after this phase.
The second part (enable_prim_token_interpretation) activates the prim
notation. It is now correctly talking to Summary and to the LibStack.
To avoid "phantom" objects in libstack after a mere Require, this
second part should be done inside a Mltop.declare_cache_obj
The link between the two parts is a prim_token_uid (a string), which
should be unique for each primitive notation. When this primitive
notation is specific to a scope, the scope_name could be used as uid.
Btw, the list of "patterns" for detecting when an uninterpreter should
be considered is now restricted to a list of global_reference
(inductive constructors, or injection functions such as IZR).
The earlier API was accepting a glob_constr list, but was actually
only working well for global_reference.
A minimal compatibility is provided (declare_numeral_interpreter),
but is discouraged, since it is known to store uncessary objects
in the libstack.