Move eu_ZIPLIB macro to m4/zip.am, new file.
diff --git a/m4/zip.m4 b/m4/zip.m4
new file mode 100644
index 0000000..398d1be
--- /dev/null
+++ b/m4/zip.m4
@@ -0,0 +1,17 @@
+dnl Test for either zlib or bzlib.
+dnl Defines --with-$1lib argument, $2LIB automake conditional,
+dnl and sets AC_DEFINE(USE_$2LIB) and LIBS.
+
+AC_DEFUN([eu_ZIPLIB], [with_[$1]lib=default
+AC_ARG_WITH([[$1]lib],
+AC_HELP_STRING([--with-[$1]lib], [support g[$1]ip compression in libdwfl]))
+if test $with_[$1]lib != no; then
+ AC_SEARCH_LIBS([$4], [$3], [with_[$1]lib=yes],
+ [test $with_[$1]lib = default ||
+ AC_MSG_ERROR([missing -l[$3] for --with-[$1]lib])])
+fi
+AM_CONDITIONAL([$2]LIB, test $with_[$1]lib = yes)
+if test $with_[$1]lib = yes; then
+ AC_DEFINE(USE_[$2]LIB)
+fi
+AH_TEMPLATE(USE_[$2]LIB, [Support $5 decompression via -l$3.])])