Make DoesIdentifierNeedQuotation public (#7365)

Author: auduchinok

src/fsharp/lexhelp.fs

@@ -351,7 +351,7 @@ module Keywords =
             | _ -> 
                 IdentifierToken args lexbuf s
 
-    let inline private DoesIdentifierNeedQuotation (s : string) : bool =
+    let DoesIdentifierNeedQuotation (s : string) : bool =
         not (String.forall IsIdentifierPartCharacter s)              // if it has funky chars
         || s.Length > 0 && (not(IsIdentifierFirstCharacter s.[0]))  // or if it starts with a non-(letter-or-underscore)
         || keywordTable.ContainsKey s                               // or if it's a language keyword like "type"

src/fsharp/lexhelp.fsi

@@ -69,6 +69,7 @@ exception IndentationProblem of string * Range.range
 module Keywords = 
     val KeywordOrIdentifierToken : lexargs -> UnicodeLexing.Lexbuf -> string -> Parser.token
     val IdentifierToken : lexargs -> UnicodeLexing.Lexbuf -> string -> Parser.token
+    val DoesIdentifierNeedQuotation : string -> bool
     val QuoteIdentifierIfNeeded : string -> string
     val NormalizeIdentifierBackticks : string -> string
     val keywordNames : string list

src/fsharp/service/ServiceLexing.fs

@@ -784,6 +784,7 @@ type FSharpSourceTokenizer(defineConstants: string list, filename: string option
 module Keywords =
     open FSharp.Compiler.Lexhelp.Keywords
 
+    let DoesIdentifierNeedQuotation s = DoesIdentifierNeedQuotation s
     let QuoteIdentifierIfNeeded s = QuoteIdentifierIfNeeded s
     let NormalizeIdentifierBackticks s = NormalizeIdentifierBackticks s
     let KeywordsWithDescription = keywordsWithDescription

src/fsharp/service/ServiceLexing.fsi

@@ -243,6 +243,9 @@ module internal TestExpose =
     val TokenInfo : Parser.token -> (FSharpTokenColorKind * FSharpTokenCharKind * FSharpTokenTriggerClass)
 
 module Keywords =
+    /// Checks if adding backticks to identifier is needed.
+    val DoesIdentifierNeedQuotation : string -> bool
+
     /// Add backticks if the identifier is a keyword.
     val QuoteIdentifierIfNeeded : string -> string