Memory usage fixes for Haddockwip/haddock-mem-fixes

- Do not include `mi_globals` in the `NoBackend` backend. It was only included
  for Haddock, but Haddock does not actually need it. This causes a 200MB
  reduction in max residency when generating haddocks on the Agda codebase
  (roughly 1GB to 800MB).
- Strictly evaluate some SrcSpans in mkDoc{Next,Prev} to avoid thunks
- Strictly evaluate names in rnHsDoc to avoid retaining entire GlobalRdrEnv
- Update Haddock submodule

1 files changed, 2 insertions, 5 deletions

diff --git a/compiler/GHC/Driver/Backend.hs b/compiler/GHC/Driver/Backend.hs
index e59f0a51f7..ab3cf3ce8d 100644
--- a/compiler/GHC/Driver/Backend.hs
+++ b/compiler/GHC/Driver/Backend.hs
@@ -551,17 +551,14 @@ backendRespectsSpecialise (Named NoBackend)   = False
 
 -- | This back end wants the `mi_globals` field of a
 -- `ModIface` to be populated (with the top-level bindings
--- of the original source).  True for the interpreter, and
--- also true for "no backend", which is used by Haddock.
--- (After typechecking a module, Haddock wants access to
--- the module's `GlobalRdrEnv`.)
+-- of the original source).  Only true for the interpreter.
 backendWantsGlobalBindings :: Backend -> Bool
 backendWantsGlobalBindings (Named NCG)         = False
 backendWantsGlobalBindings (Named LLVM)        = False
 backendWantsGlobalBindings (Named ViaC)        = False
 backendWantsGlobalBindings (Named JavaScript)  = False
+backendWantsGlobalBindings (Named NoBackend)   = False
 backendWantsGlobalBindings (Named Interpreter) = True
-backendWantsGlobalBindings (Named NoBackend)   = True
 
 -- | The back end targets a technology that implements
 -- `switch` natively.  (For example, LLVM or C.) Therefore