Run Makefile to combine benchmarks into one file.

Run `make rhino` or `make mug` to append the Rhino or Mug test runner.

Rhino can't handle real big files, so run only a few benchmarks by deleting
lines from FILES in the Makefile.  Don't delete base.js.

Ex:

make rhino
cd bin
java -cp path/to/rhino.jar org.mozilla.javascript.tools.jsc.Main v8marks_rhino.js
java -cp path/to/rhino.jar:. v8marks_rhino