Merge branch 'master' of https://github.com/fsharp/FSharp.Compiler.Service into fix-414

Author: dsyme

RELEASE_NOTES.md

@@ -1,3 +1,7 @@
+#### 2.0.0.1-beta 
+* Fix 452 - FSharpField.IsMutable = true for BCL enum cases
+* Include fix from 1.4.2.2 for #488 - Performance problems with project references
+
 #### 2.0.0.0-beta 
 * Feature #470, #478, #479 - Move ProjectCracker to separate nuget package and DLL, used ProjectCrackerTool.exe to run 
 * Feature #463 - Expose slot signatures of members in object expressions

src/fsharp/vs/Symbols.fs

@@ -656,7 +656,7 @@ and FSharpField(cenv, d: FSharpFieldData)  =
         if isUnresolved() then false else 
         match d.TryRecdField with 
         | Choice1Of2 r -> r.IsMutable
-        | Choice2Of2 f -> not f.IsInitOnly
+        | Choice2Of2 f -> not f.IsInitOnly && f.LiteralValue.IsNone
 
     member __.IsLiteral = 
         if isUnresolved() then false else