update fix to include fix for 1306

Author: dsyme

src/fsharp/TypeChecker.fs

@@ -8464,11 +8464,13 @@ and TcItemThen cenv overallTy env tpenv (item,mItem,rest,afterOverloadResolution
         let logicalCompiledName = ComputeLogicalName id memberFlags
         let traitInfo = TTrait(argTys,logicalCompiledName,memberFlags,argTys,Some retTy, sln)
 
-        AddCxMethodConstraint env.DisplayEnv cenv.css mItem NoTrace traitInfo
-      
         let expr = Expr.Op(TOp.TraitCall(traitInfo), [], ves, mItem)
         let expr = mkLambdas mItem [] vs (expr,retTy)
-        PropagateThenTcDelayed cenv overallTy env tpenv mItem (MakeApplicableExprNoFlex cenv expr) (tyOfExpr cenv.g expr) ExprAtomicFlag.NonAtomic delayed
+        let resultExpr = PropagateThenTcDelayed cenv overallTy env tpenv mItem (MakeApplicableExprNoFlex cenv expr) (tyOfExpr cenv.g expr) ExprAtomicFlag.NonAtomic delayed
+        // Add the constraint after the arguments have been checked to allow annotations to kick in on rigid type parameters
+        AddCxMethodConstraint env.DisplayEnv cenv.css mItem NoTrace traitInfo
+        resultExpr
+      
 
     | Item.DelegateCtor typ ->
         match delayed with 

tests/fsharp/core/members/ops/test.fsx

@@ -345,7 +345,13 @@ module MiscOperatorOverloadTests =
         res
 
 
+// See https://github.com/Microsoft/visualfsharp/issues/1306
+module OperatorConstraintsWithExplicitRigidTypeParameters = 
+    type M() = class end
 
+    let inline empty< ^R when ( ^R or  M) : (static member ( $ ) :  ^R *  M ->  ^R)> =        
+        let m = M()
+        Unchecked.defaultof< ^R> $ m: ^R
 
 module EnumerationOperatorTests = 
     let x1 : System.DateTimeKind =  enum 3