Workaround for these two symptoms:

Some sed tools don't match strings which are not terminated with LF.

Some shells still support the ^ as a synonym for the pipe character.

Submitted by: Stanislav Malyshev

acinclude.m4

@@ -176,7 +176,7 @@ case "[$]$1" in
 shared,*)
   ext_output="yes, shared"
   ext_shared=yes
-  $1=`echo $ac_n "[$]$1$ac_c"|sed s/^shared,//`
+  $1=`echo "[$]$1"|sed 's/^shared,//'`
   ;;
 shared)
   ext_output="yes, shared"