Add --runtime-arg to command line tools.

This shall be used in the next CL to pass -Xbootclasspath:
and -Xbootclasspath-location: that match the --image= arg.

Test: m test-art-host-gtest
Test: Manually run oatdump with --runtime-arg -Xms256m
Bug: 119868597
Change-Id: Ia355a646bf34a3314c56b9a2fb20f1ef96570fbd
2 files changed