* PPTC vs. giant ExeFS.
* InternalVersion = 2168
* Add new heuristic algorithm for calculating the number of threads for parallel translations that also takes into account the user's free physical memory and not just the number of CPU cores.
* Nit.
* Add an outer Header structure and add the hashes for both this new structure and the existing "inner" Header structure.
* InternalVersion = 2169
* PPTC & Pool Enhancements.
* Avoid buffer allocations in CodeGenContext.GetCode(). Avoid stream allocations in PTC.PtcInfo.
Refactoring/nits.
* Use XXHash128, for Ptc.Load & Ptc.Save, x10 faster than Md5.
* Why not a nice Span.
* Added a simple PtcFormatter library for deserialization/serialization, which does not require reflection, in use at PtcJumpTable and PtcProfiler; improves maintainability and simplicity/readability of affected code.
* Nits.
* Revert #1987.
* Revert "Revert #1987."
This reverts commit 998be765cf7f7da5ff0c1c08de704c9012b0f49c.
