Better debugging now in Prime code!

An ongoing issue was with Prime code being very difficult to debug because of a compiler bug forcing you to turn optimizations on in the Debug build (dotnet/fsharp#1257). Fortunately, a work-around was found (dotnet/fsharp#1257 (comment)), allowing me to finally turn the optimizations back off and make the Debug build, well, debuggable!

Thank you again, @AniAvni for your help with this!

Other than that, no major changes this release.