gnu: ghc: Really disable test that fails with glibc 2.30 and later.

This follows up commit 2e9c43aa9a, which was
incomplete.  Fixes <https://bugs.gnu.org/39358>.

* gnu/packages/patches/ghc-testsuite-dlopen-pie.patch: New file.
* gnu/local.mk (dist_patch_DATA): Adjust accordingly.  Also use tabs instead
of spaces on surrounding patches.
* gnu/packages/haskell.scm (ghc-8.6)[native-inputs]: Add patch for
"ghc-testsuite".
[arguments]: Remove incomplete workaround for the same issue.

gnu/local.mk

@@ -930,9 +930,10 @@ dist_patch_DATA =						\
   %D%/packages/patches/gd-fix-tests-on-i686.patch		\
   %D%/packages/patches/gd-freetype-test-failure.patch		\
   %D%/packages/patches/geoclue-config.patch			\
-  %D%/packages/patches/ghc-8.0-fall-back-to-madv_dontneed.patch \
-  %D%/packages/patches/ghc-diff-swap-cover-args.patch           \
+  %D%/packages/patches/ghc-8.0-fall-back-to-madv_dontneed.patch	\
+  %D%/packages/patches/ghc-testsuite-dlopen-pie.patch		\
   %D%/packages/patches/ghc-dont-pass-linker-flags-via-response-files.patch	\
+  %D%/packages/patches/ghc-diff-swap-cover-args.patch		\
   %D%/packages/patches/ghc-haddock-api-fix-haddock.patch	\
   %D%/packages/patches/ghc-hpack-fix-tests.patch		\
   %D%/packages/patches/ghc-microlens-aeson-fix-tests.patch	\

gnu/packages/haskell.scm

@@ -19,7 +19,7 @@
 ;;; Copyright © 2018, 2019 Gabriel Hondet <gabrielhondet@gmail.com>
 ;;; Copyright © 2019 Robert Vollmert <rob@vllmrt.net>
 ;;; Copyright © 2019 Jacob MacDonald <jaccarmac@gmail.com>
-;;; Copyright © Marius Bakke <mbakke@fastmail.com>
+;;; Copyright © 2020 Marius Bakke <mbakke@fastmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -568,6 +568,7 @@ interactive environment for the functional language Haskell.")
            (uri (string-append
                  "https://www.haskell.org/ghc/dist/"
                  version "/" name "-" version "-testsuite.tar.xz"))
+           (patches (search-patches "ghc-testsuite-dlopen-pie.patch"))
            (sha256
             (base32
              "0pw9r91g2np3i806g2f4f8z4jfdd7mx226cmdizk4swa7av1qf91"))))
@@ -591,12 +592,6 @@ interactive environment for the functional language Haskell.")
                  (("^test\\('T8108'") "# guix skipped: test('T8108'"))
                (substitute* "libraries/unix/tests/libposix/all.T"
                  (("^test\\('posix010'") "# guix skipped: test('posix010'"))
-               ;; This test attempts to dlopen() a position-independent
-               ;; executable(!), which is disallowed since glibc 2.30.  See
-               ;; https://sourceware.org/bugzilla/show_bug.cgi?id=24323
-               (substitute* "testsuite/tests/dynlibs/Makefile"
-                 (("\\./T13702a")
-                  "# ./T13702a"))
                #t))))))
     (native-search-paths (list (search-path-specification
                                 (variable "GHC_PACKAGE_PATH")

gnu/packages/patches/ghc-testsuite-dlopen-pie.patch

@@ -0,0 +1,54 @@
+Do not attempt to dlopen PIE objects, which was disallowed with glibc 2.30.
+
+https://gitlab.haskell.org/ghc/ghc/issues/17952
+https://sourceware.org/bugzilla/show_bug.cgi?id=24323
+
+Patch submitted upstream:
+https://gitlab.haskell.org/ghc/ghc/-/merge_requests/2947
+
+diff --git a/testsuite/tests/dynlibs/Makefile b/testsuite/tests/dynlibs/Makefile
+--- a/testsuite/tests/dynlibs/Makefile
++++ b/testsuite/tests/dynlibs/Makefile
+@@ -60,6 +60,4 @@ T5373:
+ .PHONY: T13702
+ T13702:
+ 	'$(TEST_HC)' -v0 -dynamic -rdynamic -fPIC -pie T13702.hs
+-	'$(TEST_HC)' -v0 -dynamic T13702a.hs
+-	./T13702  # first make sure executable itself works
+-	./T13702a # then try dynamically loading it as library
++	./T13702
+diff --git a/testsuite/tests/dynlibs/T13702.hs b/testsuite/tests/dynlibs/T13702.hs
+--- a/testsuite/tests/dynlibs/T13702.hs
++++ b/testsuite/tests/dynlibs/T13702.hs
+@@ -2,8 +2,3 @@
+ 
+ main :: IO ()
+ main = putStrLn "hello world"
+-
+-foreign export ccall "hello" hello :: IO ()
+-
+-hello :: IO ()
+-hello = putStrLn "hello world again"
+diff --git a/testsuite/tests/dynlibs/T13702.stdout b/testsuite/tests/dynlibs/T13702.stdout
+--- a/testsuite/tests/dynlibs/T13702.stdout
++++ b/testsuite/tests/dynlibs/T13702.stdout
+@@ -1,2 +1 @@
+ hello world
+-hello world again
+diff --git a/testsuite/tests/dynlibs/T13702a.hs b/testsuite/tests/dynlibs/T13702a.hs
+deleted file mode 100644
+--- a/testsuite/tests/dynlibs/T13702a.hs
++++ /dev/null
+@@ -1,12 +0,0 @@
+-{-# LANGUAGE ForeignFunctionInterface #-}
+-
+-import Foreign
+-import System.Posix.DynamicLinker
+-
+-main :: IO ()
+-main = do
+-    dl <- dlopen "./T13702" [RTLD_NOW]
+-    funptr <- dlsym dl "hello" :: IO (FunPtr (IO ()))
+-    mkAction funptr
+-
+-foreign import ccall "dynamic" mkAction :: FunPtr (IO ()) -> IO ()