Update the default fsharp language version to 5.0

src/fsharp/LanguageFeatures.fs

@@ -44,9 +44,9 @@ type LanguageVersion (specifiedVersionAsString) =
     static let languageVersion47 = 4.7m
     static let languageVersion50 = 5.0m
     static let previewVersion = 9999m                   // Language version when preview specified
-    static let defaultVersion = languageVersion47       // Language version when default specified
+    static let defaultVersion = languageVersion50       // Language version when default specified
     static let latestVersion = defaultVersion           // Language version when latest specified
-    static let latestMajorVersion = languageVersion47   // Language version when latestmajor specified
+    static let latestMajorVersion = languageVersion50   // Language version when latestmajor specified
 
     static let validOptions = [| "preview"; "default"; "latest"; "latestmajor" |]
     static let languageVersions = set [| languageVersion46; languageVersion47 ; languageVersion50 |]

tests/FSharp.Compiler.ComponentTests/ErrorMessages/ConstructorTests.fs

@@ -46,7 +46,7 @@ let p =
         |> typecheck
         |> shouldFail
         |> withDiagnostics [
-            (Error   39,  Line 7, Col 12, Line 7, Col 16, "The value or constructor 'Name' is not defined. Maybe you want one of the following:" + System.Environment.NewLine + "   nan")
+            (Error   39,  Line 7, Col 12, Line 7, Col 16, "The value or constructor 'Name' is not defined. Maybe you want one of the following:" + System.Environment.NewLine + "   nameof" + System.Environment.NewLine + "   nan")
             (Warning 20,  Line 7, Col 12, Line 7, Col 25, "The result of this equality expression has type 'bool' and is implicitly discarded. Consider using 'let' to bind the result to a name, e.g. 'let result = expression'.")
             (Error   39,  Line 8, Col 12, Line 8, Col 15, "The value or constructor 'Age' is not defined.")
             (Error   501, Line 7, Col 5,  Line 8, Col 21, "The object constructor 'Person' takes 0 argument(s) but is here given 1. The required signature is 'new : unit -> Person'. If some of the arguments are meant to assign values to properties, consider separating those arguments with a comma (',').")]

tests/fsharp/Compiler/Language/StringInterpolation.fs

@@ -610,8 +610,8 @@ check "vcewweh23" $"abc{({| A=1 |})}def" "abc{ A = 1 }def"
 
 
     [<Test>]
-    let ``Basic string interpolation (no preview)`` () =
-        CompilerAssert.TypeCheckWithErrorsAndOptions  [| |]
+    let ``Basic string interpolation (4.7)`` () =
+        CompilerAssert.TypeCheckWithErrorsAndOptions  [| "--langversion:4.7" |]
             """
 let x = $"one" 
             """

tests/fsharp/typecheck/overloads/neg_System.Convert.ToString.OverloadList.bsl

@@ -46,11 +46,3 @@ Available overloads:
  - System.Convert.ToString(value: uint16, provider: System.IFormatProvider) : string // Argument 'value' doesn't match
  - System.Convert.ToString(value: uint32, provider: System.IFormatProvider) : string // Argument 'value' doesn't match
  - System.Convert.ToString(value: uint64, provider: System.IFormatProvider) : string // Argument 'value' doesn't match
-
-neg_System.Convert.ToString.OverloadList.fsx(3,1,3,48): typecheck error FS0041: A unique overload for method 'ToString' could not be determined based on type information prior to this program point. A type annotation may be needed.
-
-Known types of arguments: provider:'a0 * value:int when 'a0 : null
-
-Candidates:
- - System.Convert.ToString(value: int, provider: System.IFormatProvider) : string
- - System.Convert.ToString(value: obj, provider: System.IFormatProvider) : string

tests/fsharpqa/Source/CompilerOptions/fsc/langversion/langversionhelp.437.1033.bsl

@@ -4,5 +4,5 @@ default
 latest
 latestmajor
 4.6
-4.7 (Default)
-5.0
+4.7
+5.0 (Default)

tests/fsharpqa/Source/CompilerOptions/fsi/langversion/langversionhelp.437.1033.bsl

@@ -4,5 +4,5 @@ default
 latest
 latestmajor
 4.6
-4.7 (Default)
-5.0
+4.7
+5.0 (Default)