[Truffle] Remove jruby-master so we copy over it, not into it.

Author: chrisseaton

tool/build-graal-bundles.sh

@@ -59,6 +59,8 @@ function pack {
     tar -zcf $targetname jruby-$version || exit $?
     shasum -a 1 $targetname > $targetname.sha1 || exit $?
 
+    rm -rf jruby-master || exit $?
+    
     cp -r jruby-$version jruby-master || exit $?
     targetname=jruby-dist-master+graal-$1-x86_64-bin.tar.gz
     tar -zcf $targetname jruby-master || exit $?