build improved for fedora, centos, opensuse

configure.ac

@@ -107,7 +107,7 @@ if test "$have_stacktrace" = "yes"; then
    yours])])
   AC_SEARCH_LIBS(cplus_demangle, [demangle iberty_pic iberty],
                  [AC_MSG_RESULT([OK, found cplus_demangle])],
-[AC_MSG_ERROR([Function cplus_demangle not found!
+[AC_MSG_WARN([Function cplus_demangle not found!
  - I looked in libdemangle and libiberty
  - Try "find /usr/lib -name 'libdemangle*' -o -name 'libiberty*'"
     - is one of them installed?
@@ -116,7 +116,7 @@ if test "$have_stacktrace" = "yes"; then
     - on Ubuntu (trusty) install libiberty-dev
  - Try to compile with option --disable-stacktrace
    If you are not a developer, you perhaps don't need it...?])])
-  if test "$have_dynamicstack" != "yes"; then
+if test "$have_dynamicstack" != "yes" -a "$have_cplus_demangle" = "yes"; then
     AC_DEFINE([NO_LTDL])
     AC_SEARCH_LIBS(compress, z,
                    [AC_MSG_RESULT([OK, found libz])],