[WIP] Adds optimized emit for int64 constants (#3620)
[WIP] Adds optimized emit for int64 constants (#3620)

* Adds optimized emit for int64 constants.

* Adds comment linking to the changing PR.

Thanks for this PR.

Kevin

syeerzy/visualfsharp,cloudRoutine/FSharp.Compiler.Service,cloudRoutine/FSharp.Compiler.Service,brettfo/visualfsharp,brettfo/visualfsharp,dsyme/fsharp,dsyme/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,brettfo/visualfsharp,syeerzy/visualfsharp,Jand42/FSharp.Compiler.Service,cloudRoutine/FSharp.Compiler.Service,syeerzy/visualfsharp,dsyme/FSharp.Compiler.Service,brettfo/visualfsharp,syeerzy/visualfsharp,brettfo/visualfsharp,ncave/FSharp.Compiler.Service,dsyme/FSharp.Compiler.Service,dsyme/fsharp,syeerzy/visualfsharp,Jand42/FSharp.Compiler.Service,fsharp/fsharp,fsharp/fsharp,dsyme/fsharp,Jand42/FSharp.Compiler.Service,ncave/FSharp.Compiler.Service,brettfo/visualfsharp,dsyme/fsharp,dsyme/fsharp,fsharp/fsharp,syeerzy/visualfsharp,dsyme/fsharp,dsyme/fsharp