Patch ltmain.sh to provide NAG compiler with -Wl,-pthread.

autogen.sh

+#!/bin/sh
+
+autoreconf -fvi || exit $?
+patch -p 1 -i patch/ltmain_sh.patch -d .

patch/ltmain_sh.patch

+diff --git a/config/ltmain.sh b/config/ltmain.sh
+index b6f3fcbb..4facc967 100644
+--- a/config/ltmain.sh
++++ b/config/ltmain.sh
+@@ -7861,6 +7861,13 @@ func_mode_link ()
+ 	# Read the .la file
+ 	func_source "$lib"
+ 
++	# Change -pthread to -Wl,-pthread for nagfor
++	if test -n "$inherited_linker_flags"; then
++	  case $CC in
++	    nagfor*) inherited_linker_flags=`$ECHO "$inherited_linker_flags" | $SED 's/ -pthread/ -Wl,-pthread/g'` ;;
++	  esac
++	fi
++
+ 	# Convert "-framework foo" to "foo.ltframework"
+ 	if test -n "$inherited_linker_flags"; then
+ 	  tmp_inherited_linker_flags=`$ECHO "$inherited_linker_flags" | $SED 's/-framework \([^ $]*\)/\1.ltframework/g'`