Put hole instantiation typechecking in the module graph and fix driver batch mode backpack edges

Backpack instantiations need to be typechecked to make sure that the
arguments fit the parameters. `tcRnInstantiateSignature` checks
instantiations with concrete modules, while `tcRnCheckUnit` checks
instantiations with free holes (signatures in the current modules).

Before this change, it worked that `tcRnInstantiateSignature` was called
after typechecking the argument module, see `HscMain.hsc_typecheck`,
while `tcRnCheckUnit` was called in `unsweep'` where-bound in
`GhcMake.upsweep`. `tcRnCheckUnit` was called once per each
instantiation once all the argument sigs were processed. This was done
with simple "to do" and "already done" accumulators in the fold.
`parUpsweep` did not implement the change.

With this change, `tcRnCheckUnit` instead is associated with its own
node in the `ModuleGraph`. Nodes are now:
```haskell
data ModuleGraphNode
  -- | Instantiation nodes track the instantiation of other units
  -- (backpack dependencies) with the holes (signatures) of the current package.
  = InstantiationNode InstantiatedUnit
  -- | There is a module summary node for each module, signature, and boot module being built.
  | ModuleNode ExtendedModSummary
```
instead of just `ModSummary`; the `InstantiationNode` case is the
instantiation of a unit to be checked. The dependencies of such nodes
are the same "free holes" as was checked with the accumulator before.
Both versions of upsweep on such a node call `tcRnCheckUnit`.

There previously was an `implicitRequirements` function which would
crawl through every non-current-unit module dep to look for all free
holes (signatures) to add as dependencies in `GHC.Driver.Make`. But this
is no good: we shouldn't be looking for transitive anything when
building the graph: the graph should only have immediate edges and the
scheduler takes care that all transitive requirements are met.

So `GHC.Driver.Make` stopped using `implicitRequirements`, and instead
uses a new `implicitRequirementsShallow`, which just returns the
outermost instantiation node (or module name if the immediate dependency
is itself a signature). The signature dependencies are just treated like
any other imported module, but the module ones then go in a list stored
in the `ModuleNode` next to the `ModSummary` as the "extra backpack
dependencies". When `downsweep` creates the mod summaries, it adds this
information too.

------

There is one code quality, and possible correctness thing left: In
addition to `implicitRequirements` there is `findExtraSigImports`, which
says something like "if you are an instantiation argument (you are
substituted or a signature), you need to import its things too".  This
is a little non-local so I am not quite sure how to get rid of it in
`GHC.Driver.Make`, but we probably should eventually.

First though, let's try to make a test case that observes that we don't
do this, lest it actually be unneeded. Until then, I'm happy to leave it
as is.

------

Beside the ability to use `-j`, the other major user-visibile side
effect of this change is that that the --make progress log now includes
"Instantiating" messages for these new nodes. Those also are numbered
like module nodes and count towards the total.

------

Fixes #17188

Updates hackage submomdule

Metric Increase:
    T12425
    T13035

1 files changed, 7 insertions, 4 deletions

diff --git a/ghc/GHCi/UI.hs b/ghc/GHCi/UI.hs
index 152017de38..4a1b91a9fc 100644
--- a/ghc/GHCi/UI.hs
+++ b/ghc/GHCi/UI.hs
@@ -76,6 +76,7 @@ import qualified GHC.Parser.Lexer as Lexer
 import GHC.Unit
 import GHC.Unit.State
 import GHC.Unit.Finder as Finder
+import GHC.Unit.Module.Graph (filterToposortToModules)
 import GHC.Unit.Module.ModSummary
 
 import GHC.Data.StringBuffer
@@ -1632,8 +1633,9 @@ chooseEditFile =
 
      graph <- GHC.getModuleGraph
      failed_graph <-
-       GHC.mkModuleGraph <$> filterM hasFailed (GHC.mgModSummaries graph)
-     let order g  = flattenSCCs $ GHC.topSortModuleGraph True g Nothing
+       GHC.mkModuleGraph . fmap extendModSummaryNoDeps <$> filterM hasFailed (GHC.mgModSummaries graph)
+     let order g  = flattenSCCs $ filterToposortToModules $
+           GHC.topSortModuleGraph True g Nothing
          pick xs  = case xs of
                       x : _ -> GHC.ml_hs_file (GHC.ms_location x)
                       _     -> Nothing
@@ -2018,8 +2020,9 @@ setContextAfterLoad keep_ctxt ms = do
   targets <- GHC.getTargets
   case [ m | Just m <- map (findTarget ms) targets ] of
         []    ->
-          let graph = GHC.mkModuleGraph ms
-              graph' = flattenSCCs (GHC.topSortModuleGraph True graph Nothing)
+          let graph = GHC.mkModuleGraph $ extendModSummaryNoDeps <$> ms
+              graph' = flattenSCCs $ filterToposortToModules $
+                GHC.topSortModuleGraph True graph Nothing
           in load_this (last graph')
         (m:_) ->
           load_this m