cleanup to reduce surface areas in this repo and align

Author: dsyme

src/fsharp/CompileOps.fs

@@ -40,7 +40,6 @@ open Microsoft.FSharp.Compiler.MSBuildResolver
 open Microsoft.FSharp.Compiler.TypeRelations
 open Microsoft.FSharp.Compiler.NameResolution
 open Microsoft.FSharp.Compiler.PrettyNaming
-open Internal.Utilities.FileSystem
 open Internal.Utilities.Collections
 open Internal.Utilities.Filename
 open Microsoft.FSharp.Compiler.Import

src/fsharp/ExtensionTyping.fs

@@ -17,7 +17,6 @@ module internal ExtensionTyping =
     open Microsoft.FSharp.Compiler.AbstractIL.IL
     open Microsoft.FSharp.Compiler.AbstractIL.Diagnostics // dprintfn
     open Microsoft.FSharp.Compiler.AbstractIL.Internal.Library // frontAndBack
-    open Internal.Utilities.FileSystem
 
 #if TYPE_PROVIDER_SECURITY
     module internal GlobalsTheLanguageServiceCanPoke =