Expose all unfoldings of overloaded functions by default

Users expect their overloaded functions to be specialised at call sites, however, this is only the case if they are either lucky and GHC chooses to include the unfolding or they mark their definition with an INLINABLE pragma. This leads to library authors marking all their functions with INLINABLE (or more accurately INLINE) so they ensure that downstream consumers pay no cost for their abstraction.

A more sensible default is to do this job for the library author and give more predictable guarantees about specialisation.

Empirically, I compiled a selection of 1150 packages with (a similar) patch applied. The total size of the interface files before the patch was 519mb and after 634mb. On modern machines, I think this increase is justified for the result.

This is a ticket to track the progress of D2929.

Trac metadata

Trac field	Value
Version	8.0.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture