Runtime compressed refs builds

[gacholio]

To build runtime compressed refs today, I delete the default directory and symlink it to the compressedrefs directory.

For a real mixed build, we need a single VM directory.

There are several things to consider:

• redirector makes the compressed/full decision based on heap size

In the most basic scenario, the redirector will need to add -Xcompressedrefs or -Xnocompressedrefs to the command line rather than selecting a VM

• redirector is no longer needed at all

For the purposes of this feature, the redirector could just be deleted. There are other reasons to keep this alive (future VM extensions like the past -Xaggressive). Might be nice to make it optional, though that brings its own technical debt.

I suggest that we stick with default as the VM directory for mixed. This is consistent with adding future selectable VMs.

Related: #9231

[gacholio]

@DanHeidinga

[DanHeidinga]

In the most basic scenario, the redirector will need to add -Xcompressedrefs or -Xnocompressedrefs to the command line rather than selecting a VM

This makes sense to me. Keeping the redirector is the right decision as we make this transition to the single VM as it gives us the ability to fall back if necessary and provides the most straightforward way to move from multi to single package.

There are other reasons to keep this alive (future VM extensions like the past -Xaggressive).

+1 to keeping this flexibility, especially as we look at future areas. I'd be happy if we don't need to use it but don't want to lose it (yet).

I suggest that we stick with default as the VM directory for mixed. This is consistent with adding future selectable VMs.

Agreed. default as the package for the single combined VM is the right choice.