Support for IR compiler

[ethanmdavidson]

kotlin/JS is moving to a new compiler, so libraries should use "BOTH" compilation mode to ease the transition. Some code changes may be necessary. Additionally, all dependencies (i.e. cobalt) will need to be built in BOTH mode.

I tried changing cobalt to BOTH and it seemed to build fine, but when I published to mavenLocal and tried to use it in amethyst ran into issues (Unresolved reference: cobalt on every import statement).