Make the External Package Table contain ModDetails not ModIface

Currently the External Package Table contains ModIfaces. But that makes it hard to answer the question "which instances were introduced by module Foo" in the GHC API. See Kenny Lu's problem http://www.haskell.org/pipermail/glasgow-haskell-users/2007-August/013027.html

Furthermore the ModIfaces in the EPS are cut-down ones, with decls etc trimmed off becuase they are in the type envts.

Since loadInterface does typechecking etc, it'd make sense for it to return a ModDetails instead and for that ModDetails to be stored in the EPS. This would also tidy up the oddity that a ModIface contains redundant fields for fixity envt and deprecaction envt (they would move to ModDetails).

Then it'd also make sense for the GHC API to use ModDetails instead of ModInfo.

This change isn't truly hard, but it needs care.

Trac metadata

Trac field	Value
Version	6.6.1
Type	Task
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system	Unknown
Architecture	Unknown

changed weight to 5

added Ttask Trac import labels

See also #1617 (closed), and Simon's comment on the patch:

Wed Nov  7 08:14:54 PST 2007  Simon Marlow <simonmar@microsoft.com>
  * FIX #1617: reloading didn't change the :browse output as it should
  The problem was that because the interface hadn't changed, we were
  re-using the old ModIface.  Unfortunately the ModIface contains the
  GlobalRdrEnv for the module, and that *had* changed.  The fix is to
  put the new GlobalRdrEnv in the ModIface even if the interface has not
  otherwise changed.

  ModIface is not really the right place for the GlobalRdrEnv, but
  neither is ModDetails, so we should think about a better way to do
  this.

Trac metadata

Trac field	Value
Architecture	Unknown → Unknown/Multiple

Trac metadata

Trac field	Value
Operating system	Unknown → Unknown/Multiple

changed milestone to %6.12 branch

changed milestone to %6.12.3

removed milestone

changed weight to 3

Trac metadata

Trac field	Value
Priority	normal → low

changed milestone to %7.0.2

changed milestone to %7.2.1

changed milestone to %7.4.1

changed milestone to %7.6.1

changed weight to 0

Trac metadata

Trac field	Value
Priority	low → lowest

changed milestone to %7.6.2

Bump; time for another look?

Trac metadata

Trac field	Value
TypeOfFailure	- → OtherFailure

changed milestone to %7.10.1

Moving to 7.10.1.