Revert "Remove Autotools sed hack (HDFGroup#3848)"

This reverts commit 8b3ffde.

configure.ac

@@ -4613,5 +4613,11 @@ if test "X$HDF_FORTRAN" = "Xyes"; then
   esac
 fi
 
+## HDF5 configure code created by autotools with gcc 4.9.2 is adding problematic
+## linker flags:  -l with no library name; -l <libname>, specifically gfortran or m.
+## This sed script corrects "-l <libname>" first and then "-l " with no library name.
+## If the order is not preserved, all instances of "-l " will be removed.
+sed -e '/^postdeps/ s/-l \([a-zA-Z]\)/-l\1/g' -e '/^postdeps/ s/-l //g' -i libtool
+
 ## show the configure settings
 cat src/libhdf5.settings

release_docs/RELEASE.txt

@@ -1701,16 +1701,6 @@ Bug Fixes since HDF5-1.14.0 release
         * HDF5_ENABLE_DOXY_WARNINGS: ON/OFF (Default: OFF)
         * --enable-doxygen-errors: enable/disable (Default: disable)
 
-    - Removed an Autotools configure hack that causes problems on MacOS
-
-      A sed line in configure.ac was added in the past to paper over some
-      problems with older versions of the Autotools that would add incorrect
-      linker flags. This hack is not needed with recent versions of the
-      Autotools and the sed line errors on MacOS (though this was a silent
-      error that didn't break the build) so the hack has been removed.
-
-      Fixes GitHub issue #3843
-
     - Fixed an issue where the h5tools_test_utils test program was being
       installed on the system for Autotools builds of HDF5