more ambitious scalac options for makedist;

--- a/Admin/makedist	Sun Mar 18 21:52:50 2012 +0100
+++ b/Admin/makedist	Sun Mar 18 22:06:37 2012 +0100
@@ -145,6 +145,8 @@
 find . "(" -name \*.thy -o -name \*.ML ")" -perm +111 -print | xargs chmod -f -x
 find . -print | xargs chmod -f u+rw
 
+perl -pi -e 's/^(ISABELLE_SCALA_BUILD_OPTIONS=")/$1-optimise /,' etc/settings
+
 ./Admin/build all || fail "Failed to build distribution"
 
 if [ -n "$ISABELLE_JEDIT_BUILD_HOME" ]; then