Add support for BeOS, which doesn't have libm.

src/configure

@@ -1304,6 +1304,48 @@ done
 
                       fi
 fi
+echo $ac_n "checking for rand in -lm""... $ac_c" 1>&6
+echo "configure:1309: checking for rand in -lm" >&5
+ac_lib_var=`echo m'_'rand | sed 'y%./+-%__p_%'`
+if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
+  echo $ac_n "(cached) $ac_c" 1>&6
+else
+  ac_save_LIBS="$LIBS"
+LIBS="-lm  $LIBS"
+cat > conftest.$ac_ext <<EOF
+#line 1317 "configure"
+#include "confdefs.h"
+/* Override any gcc2 internal prototype to avoid an error.  */
+/* We use char because int might match the return type of a gcc2
+    builtin and then its argument prototype would still apply.  */
+char rand();
+
+int main() {
+rand()
+; return 0; }
+EOF
+if { (eval echo configure:1328: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+  rm -rf conftest*
+  eval "ac_cv_lib_$ac_lib_var=yes"
+else
+  echo "configure: failed program was:" >&5
+  cat conftest.$ac_ext >&5
+  rm -rf conftest*
+  eval "ac_cv_lib_$ac_lib_var=no"
+fi
+rm -f conftest*
+LIBS="$ac_save_LIBS"
+
+fi
+if eval "test \"`echo '$ac_cv_lib_'$ac_lib_var`\" = yes"; then
+  echo "$ac_t""yes" 1>&6
+  GPERF_LIBM="-lm"
+else
+  echo "$ac_t""no" 1>&6
+GPERF_LIBM=""
+fi
+
+
 trap '' 1 2 15
 cat > confcache <<\EOF
 # This file is a shell script that caches the results of configure
@@ -1444,6 +1486,7 @@ s%@CXXCPP@%$CXXCPP%g
 s%@INSTALL@%$INSTALL%g
 s%@INSTALL_PROGRAM@%$INSTALL_PROGRAM%g
 s%@INSTALL_DATA@%$INSTALL_DATA%g
+s%@GPERF_LIBM@%$GPERF_LIBM%g
 
 CEOF
 EOF