1380030 - Remove color constants from public API and replace with an internal MarkColor enum.
1380030 - Simplify and refactor use of isMarked*() methods.
I only had one part of this before: Refactor isMarked() methods into separate methods for each color and any.
903519 Part 6: Strings in the nursery: tracing and tenuring.
903519 Part 7: Strings in the nursery: barriers.
903519 Part 8: Discard nursery keys from EvalCache.
903519 Part 9: Strings in the nursery: allow any thread to access zone of permanent atoms.
903519 Part 10: Strings in the nursery: MIR node.
903519 Part 11: Change Relocated marker to not confuse string vs object bit.
903519 Part 12: Default nursery strings to off, add ability to enable.
903519 Part 13: Strings in the nursery: JIT, partial due CodeGenerator.cpp differences startin from: // Follow any base pointer if the input is itself a dependent string.
This is due file changed: 1434230: Spectre mitigations for strings
