Compute Severity of diagnostics at birth

This commit further expand on the design for #18516 by getting rid of
the `defaultReasonSeverity` in favour of a function called
`diagReasonSeverity` which correctly takes the `DynFlags` as input. The
idea is to compute the `Severity` and the `DiagnosticReason` of each
message "at birth", without doing any later re-classifications, which
are potentially error prone, as the `DynFlags` might evolve during the
course of the program.

In preparation for a proper refactoring, now `pprWarning` from the
Parser.Ppr module has been renamed to `mkParserWarn`, which now takes a
`DynFlags` as input.

We also get rid of the reclassification we were performing inside `printOrThrowWarnings`.

Last but not least, this commit removes the need for reclassify inside GHC.Tc.Errors,
and also simplifies the implementation of `maybeReportError`.

Update Haddock submodule

3 files changed, 5 insertions, 5 deletions

diff --git a/utils/check-exact/Parsers.hs b/utils/check-exact/Parsers.hs
index eccf3f2612..f1437869ee 100644
--- a/utils/check-exact/Parsers.hs
+++ b/utils/check-exact/Parsers.hs
@@ -87,7 +87,7 @@ parseWith :: GHC.DynFlags
           -> ParseResult w
 parseWith dflags fileName parser s =
   case runParser parser dflags fileName s of
-    GHC.PFailed pst                     -> Left (fmap GHC.pprError $ GHC.getErrorMessages pst)
+    GHC.PFailed pst                     -> Left (fmap GHC.mkParserErr $ GHC.getErrorMessages pst)
     GHC.POk _ pmod -> Right pmod
 
 
@@ -101,7 +101,7 @@ parseWithECP dflags fileName parser s =
     -- case runParser ff dflags fileName s of
     -- case runParser (parser >>= \p -> GHC.runECP_P p) dflags fileName s of
     case runParser (parser >>= \p -> GHC.runPV $ GHC.unECP p) dflags fileName s of
-      GHC.PFailed pst                     -> Left (fmap GHC.pprError $ GHC.getErrorMessages pst)
+      GHC.PFailed pst                     -> Left (fmap GHC.mkParserErr $ GHC.getErrorMessages pst)
       GHC.POk _ pmod -> Right pmod
 
 -- ---------------------------------------------------------------------
@@ -192,7 +192,7 @@ parseModuleFromStringInternal :: Parser GHC.ParsedSource
 parseModuleFromStringInternal dflags fileName str =
   let (str1, lp) = stripLinePragmas str
       res        = case runParser GHC.parseModule dflags fileName str1 of
-        GHC.PFailed pst     -> Left (fmap GHC.pprError $ GHC.getErrorMessages pst)
+        GHC.PFailed pst     -> Left (fmap GHC.mkParserErr $ GHC.getErrorMessages pst)
         GHC.POk     _  pmod -> Right (lp, dflags, pmod)
   in  postParseTransform res
 
@@ -263,7 +263,7 @@ parseModuleEpAnnsWithCppInternal cppOptions dflags file = do
         return (contents1,lp,dflags)
   return $
     case parseFile dflags' file fileContents of
-      GHC.PFailed pst -> Left (fmap GHC.pprError $ GHC.getErrorMessages pst)
+      GHC.PFailed pst -> Left (fmap GHC.mkParserErr $ GHC.getErrorMessages pst)
       GHC.POk _ pmod  ->
         Right $ (injectedComments, dflags', pmod)
 
diff --git a/utils/check-exact/Preprocess.hs b/utils/check-exact/Preprocess.hs
index 761029adb2..904e76938e 100644
--- a/utils/check-exact/Preprocess.hs
+++ b/utils/check-exact/Preprocess.hs
@@ -277,7 +277,7 @@ parseError pst = do
      let
        -- (warns,errs) = GHC.getMessages pst dflags
      -- throw $ GHC.mkSrcErr (GHC.unitBag $ GHC.mkPlainErrMsg dflags sspan err)
-     GHC.throwErrors (fmap GHC.pprError (GHC.getErrorMessages pst))
+     GHC.throwErrors (fmap GHC.mkParserErr (GHC.getErrorMessages pst))
 
 -- ---------------------------------------------------------------------
 
diff --git a/utils/haddock b/utils/haddock
-Subproject c623c7d2df417caac4b72b747ef5262d86ee776
+Subproject eebc74dc08987fdd9b1c289be38207af9b0334c