7122880: Extend vendor-specific command interface to include manageable switches Summary: Add Flag::external_ext()/writable_ext(), both return false. Reviewed-by: coleenp, zgu

7122939: TraceBytecodes broken with UseCompressedOops Summary: Disable verify_heapbase on sparc if TraceBytecodes because the latter uses r12 as a temp register Reviewed-by: coleenp, phh Contributed-by: Volker Simonis <volker.simonis@gmail.com>