Fake.Core.Process: stop using old ref-cell operators

[knocte]

The new version of the F# compiler now flags these occurrences as deprecated.

The messages are of two kinds:

1. info FS3370: The use of ':=' from the F# library is deprecated.
   See https://aka.ms/fsharp-refcell-ops.
   For example, please change 'cell := expr' to 'cell.Value <- expr'.

2. info FS3370: The use of '!' from the F# library is deprecated.
   See https://aka.ms/fsharp-refcell-ops.
   For example, please change '!cell' to 'cell.Value'.

[knocte]

Oops, CI was failing because I made a typo (forgot a <- operator) in one line. Fixed. CI should be green now.

[yazeedobaid]

Hi thanks for the PR
Could you please rebase your branch from release/next? Now that the build has been fixed.

[knocte]

Could you please rebase your branch from release/next?

Done.

[yazeedobaid]

Can you please check if other parts of the FAKE repo have usage for these operators and replace them the same way?
If it is a lot of work, I'm ok with merging this PR, and then we can open an issue to track other parts and merge them in small chunks. Or in this PR. Whatever works best for you.

[knocte]

% grep ":=" -ri . | grep -v legacy | grep -v Binary
./src/app/Fake.Runtime/YaafFSharpScripting.fs:          __hook := obj
./src/app/Fake.Runtime/YaafFSharpScripting.fs:                  isDisposed := true }
./src/app/Fake.Runtime/YaafFSharpScripting.fs:                  isDisposed := true }
./src/app/Fake.Runtime/YaafFSharpScripting.fs:              properEndLine := false
./src/app/Fake.Runtime/YaafFSharpScripting.fs:              properEndLine := true
./src/app/Fake.Runtime/ScriptRunner.fs:    //__hook := execContext
./src/app/Fake.Runtime/LegacyApiHelper.fs:let ofRef r = { Set = (fun v -> r := v); Get = (fun () -> !r) }
./src/app/Fake.DotNet.FxCop/FxCop.fs:      Item "/ruleset:=%s" param.CustomRuleset
./src/app/Fake.IO.FileSystem/Path.fs:            resultPath := !resultPath + directorySeparator + ".."
./src/app/Fake.IO.FileSystem/Path.fs:            baseLocation := Path.GetDirectoryName !baseLocation
./src/app/Fake.IO.FileSystem/Path.fs:                baseLocation := (!baseLocation).Substring(0, (!baseLocation).Length - 1)
./src/app/Fake.IO.FileSystem/Path.fs:        := (!resultPath + targetLocation.Substring((!baseLocation).Length)) 
./src/app/Fake.IO.FileSystem/ChangeWatcher.fs:                    unNotifiedChanges := []
./src/app/Fake.IO.FileSystem/ChangeWatcher.fs:                        runningHandlers := true
./src/app/Fake.IO.FileSystem/ChangeWatcher.fs:                        runningHandlers := false )
./src/app/Fake.IO.FileSystem/ChangeWatcher.fs:                  unNotifiedChanges := fileChange :: !unNotifiedChanges
./src/app/Fake.IO.FileSystem/Shell.fs:                i := !i + 1
./src/app/Fake.JavaScript.Npm/Npm.fs:            if exitCode <> 0 then result := Some(sprintf "exit code: %d" exitCode)
./src/app/Fake.JavaScript.Npm/Npm.fs:            if not (isNull exn.InnerException) then message := !message + Environment.NewLine + exn.InnerException.Message
./src/app/Fake.JavaScript.Npm/Npm.fs:            result := Some(!message)
./src/app/Fake.IO.Zip/Zip.fs:        length := !length - (int64 count)
./src/app/Fake.Core.CommandLineParsing/docopt.fs/Docopt/OptionsParser.fs:        lastOpt := Some opt
./src/app/Fake.Core.Process/InternalStreams.fs:                    first := false
./src/app/Fake.Core.Process/InternalStreams.fs:                        closed := true } |> Async.Start
./src/app/Fake.Core.Process/InternalStreams.fs:        //                current := next
./src/app/Fake.Core.Process/InternalStreams.fs:                            closeRead :=
./src/app/Fake.Core.Process/InternalStreams.fs:                                    streamFinished := true
./src/app/Fake.Core.Process/InternalStreams.fs:                    closeRead := true
./src/app/Fake.Core.Process/Process.fs:                              traced := true
./src/app/Fake.Core.Process/Process.fs:            messages := { IsError = isError
./src/app/Fake.Core.Process/GuardedAwaitObservable.fs:        let setRemover r = lock removeLock (fun () -> removeObj := Some r)
./src/app/Fake.Core.Process/GuardedAwaitObservable.fs:                    removeObj := None
./src/test/Fake.Core.UnitTests/Fake.DotNet.FxCop.fs:                    wrap "/ruleset:=" p.CustomRuleset

Seems like a lot of work to me, I'd prefer if other contributor finishes it.

[yazeedobaid]

Thanks for the PR, other places that use old ref-cell operators are replaced in v6 branch.