Fix a few broken Trac links [skip ci]

This patch only attempts to fix links that don't automatically re-direct to the correct URL.

README.md

@@ -108,7 +108,8 @@ groups from around the world. We'd like to thank them all, and invite
 you to join!
 
   [1]:  http://www.haskell.org/ghc/            "www.haskell.org/ghc/"
-  [2]:  http://ghc.haskell.org/trac/ghc    "ghc.haskell.org/trac/ghc"
+  [2]:  https://gitlab.haskell.org/ghc/ghc/issues
+          "gitlab.haskell.org/ghc/ghc/issues"
   [3]:  https://gitlab.haskell.org/ghc/ghc/wikis/building
           "https://gitlab.haskell.org/ghc/ghc/wikis/building"
   [4]:  http://www.haskell.org/happy/          "www.haskell.org/happy/"

compiler/deSugar/Check.hs

@@ -2332,7 +2332,7 @@ term constraints (respectively) as we go deeper.
 
 The type constraints we propagate inwards are collected by `collectEvVarsPats'
 in HsPat.hs. This handles bug #4139 ( see example
-  https://ghc.haskell.org/trac/ghc/attachment/ticket/4139/GADTbug.hs )
+  https://gitlab.haskell.org/ghc/ghc/snippets/672 )
 where this is needed.
 
 For term equalities we do less, we just generate equalities for HsCase. For

libraries/base/base.cabal

@@ -6,7 +6,7 @@ version:        4.13.0.0
 license:        BSD-3-Clause
 license-file:   LICENSE
 maintainer:     libraries@haskell.org
-bug-reports:    http://ghc.haskell.org/trac/ghc/newticket?component=libraries/base
+bug-reports:    https://gitlab.haskell.org/ghc/ghc/issues/new
 synopsis:       Basic libraries
 category:       Prelude
 build-type:     Configure

libraries/ghc-boot-th/ghc-boot-th.cabal.in

@@ -8,7 +8,7 @@ license:        BSD3
 license-file:   LICENSE
 category:       GHC
 maintainer:     ghc-devs@haskell.org
-bug-reports:    https://ghc.haskell.org/trac/ghc/newticket
+bug-reports:    https://gitlab.haskell.org/ghc/ghc/issues/new
 synopsis:       Shared functionality between GHC and the @template-haskell@
                 library
 description:    This library contains various bits shared between the @ghc@ and

libraries/ghc-boot/ghc-boot.cabal.in

@@ -8,7 +8,7 @@ license:        BSD3
 license-file:   LICENSE
 category:       GHC
 maintainer:     ghc-devs@haskell.org
-bug-reports:    https://ghc.haskell.org/trac/ghc/newticket
+bug-reports:    https://gitlab.haskell.org/ghc/ghc/issues/new
 synopsis:       Shared functionality between GHC and its boot libraries
 description:    This library is shared between GHC, ghc-pkg, and other boot
                 libraries.

libraries/ghc-compact/ghc-compact.cabal

@@ -4,7 +4,7 @@ version:        0.1.0.0
 license:        BSD3
 license-file:   LICENSE
 maintainer:     libraries@haskell.org
-bug-reports:    http://ghc.haskell.org/trac/ghc/newticket?component=libraries/ghc-compact
+bug-reports:    https://gitlab.haskell.org/ghc/ghc/issues/new
 synopsis:       In memory storage of deeply evaluated data structure
 category:       Data
 description:

libraries/ghc-heap/GHC/Exts/Heap/Closures.hs

@@ -100,7 +100,7 @@ areBoxesEqual (Box a) (Box b) = case reallyUnsafePtrEqualityUpToTag# a b of
 type Closure = GenClosure Box
 
 -- | This is the representation of a Haskell value on the heap. It reflects
--- <http://ghc.haskell.org/trac/ghc/browser/includes/rts/storage/Closures.h>
+-- <https://gitlab.haskell.org/ghc/ghc/blob/master/includes/rts/storage/Closures.h>
 --
 -- The data type is parametrized by the type to store references in. Usually
 -- this is a 'Box' with the type synonym 'Closure'.

libraries/ghc-heap/GHC/Exts/Heap/InfoTable/Types.hsc

@@ -28,7 +28,7 @@ type HalfWord = Word16
 type EntryFunPtr = FunPtr (Ptr () -> IO (Ptr ()))
 
 -- | This is a somewhat faithful representation of an info table. See
--- <http://ghc.haskell.org/trac/ghc/browser/includes/rts/storage/InfoTables.h>
+-- <https://gitlab.haskell.org/ghc/ghc/blob/master/includes/rts/storage/InfoTables.h>
 -- for more details on this data structure.
 data StgInfoTable = StgInfoTable {
    entry  :: Maybe EntryFunPtr, -- Just <=> not ghciTablesNextToCode

libraries/ghc-heap/ghc-heap.cabal.in

@@ -4,7 +4,7 @@ version:        @ProjectVersionMunged@
 license:        BSD-3-Clause
 license-file:   LICENSE
 maintainer:     libraries@haskell.org
-bug-reports:    http://ghc.haskell.org/trac/ghc/newticket
+bug-reports:    https://gitlab.haskell.org/ghc/ghc/issues/new
 synopsis:       Functions for walking GHC's heap
 category:       GHC
 description:

libraries/ghc-prim/ghc-prim.cabal

@@ -6,7 +6,7 @@ license:        BSD-3-Clause
 license-file:   LICENSE
 category:       GHC
 maintainer:     libraries@haskell.org
-bug-reports:    http://ghc.haskell.org/trac/ghc/newticket?component=libraries%20%28other%29&keywords=ghc-prim
+bug-reports:    https://gitlab.haskell.org/ghc/ghc/issues/new
 synopsis:       GHC primitives
 build-type:     Custom
 description:

libraries/template-haskell/template-haskell.cabal.in

@@ -9,7 +9,7 @@ license:        BSD3
 license-file:   LICENSE
 category:       Template Haskell
 maintainer:     libraries@haskell.org
-bug-reports:    http://ghc.haskell.org/trac/ghc/newticket?component=Template%20Haskell
+bug-reports:    https://gitlab.haskell.org/ghc/ghc/issues/new
 synopsis:       Support library for Template Haskell
 build-type:     Simple
 Cabal-Version:  >= 1.10