gnu: Add hdf4

* gnu/packages/maths.scm (hdf4, hdf4-alt): New variables.
* gnu/packages/patches/hdf4-reproducibility.patch: New file.
* gnu/packages/patches/hdf4-shared-fortran.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add patches.

Co-Authored-By: Jeremy Robst <jpro@bas.ac.uk>

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/patches/hdf4-shared-fortran.patch

@@ -0,0 +1,25 @@
+Allow building a shared library with Fortran.
+---
+ configure | 6 ------
+ 1 file changed, 6 deletions(-)
+
+diff --git a/configure b/configure
+index f37d2fa..eb9f346 100755
+--- a/configure
++++ b/configure
+@@ -6141,12 +6141,6 @@ if test "X${enable_shared}" != "Xyes"; then
+     enable_shared="no"
+ fi
+ 
+-if test "X${enable_shared}" = "Xyes"; then
+-    if test "X${BUILD_FORTRAN}" = "Xyes"; then
+-        as_fn_error $? "Cannot build shared fortran libraries. Please configure with --disable-fortran flag." "$LINENO" 5
+-    fi
+-fi
+-
+ 
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ln -s works" >&5
+ $as_echo_n "checking whether ln -s works... " >&6; }
+-- 
+2.10.0
+