No diagnostic about static member in object expression (#16277)

* No diagnostic about static member in object expression

* Move object expressions tests to its own file and improve testing in general

* Update src/Compiler/Checking/MethodOverrides.fs

Co-authored-by: Adam Boniecki <20281641+abonie@users.noreply.github.com>

* Update tests/FSharp.Compiler.ComponentTests/Conformance/Expressions/ObjectExpression/ObjectExpression.fs

Co-authored-by: Petr <psfinaki@users.noreply.github.com>

* Renaming

* more tests

* Improve error message and tests

---------

Co-authored-by: Adam Boniecki <20281641+abonie@users.noreply.github.com>
Co-authored-by: Petr <psfinaki@users.noreply.github.com>

src/Compiler/Checking/CheckExpressions.fs

@@ -7033,6 +7033,10 @@ and TcObjectExpr (cenv: cenv) env tpenv (objTy, realObjTy, argopt, binds, extraI
         // 2. check usage conditions
         overridesAndVirts |> List.iter (fun (m, implTy, dispatchSlots, dispatchSlotsKeyed, availPriorOverrides, overrides) ->
             let overrideSpecs = overrides |> List.map fst
+            let hasStaticMembers = dispatchSlots |> List.exists (fun reqdSlot -> not reqdSlot.MethodInfo.IsInstance)
+
+            if hasStaticMembers then
+                errorR(Error(FSComp.SR.chkStaticMembersOnObjectExpressions(), mObjTy))
 
             DispatchSlotChecking.CheckOverridesAreAllUsedOnce (env.DisplayEnv, g, cenv.infoReader, true, implTy, dispatchSlotsKeyed, availPriorOverrides, overrideSpecs)
 

src/Compiler/Checking/MethodOverrides.fs

@@ -379,8 +379,9 @@ module DispatchSlotChecking =
                     // error reporting path
                     let compiledSig = CompiledSigOfMeth g amap m dispatchSlot
 
-                    let noimpl() = 
-                        missingOverloadImplementation.Add((isReqdTyInterface, lazy NicePrint.stringOfMethInfo infoReader m denv dispatchSlot))
+                    let noimpl() =
+                        if dispatchSlot.IsInstance then
+                            missingOverloadImplementation.Add((isReqdTyInterface, lazy NicePrint.stringOfMethInfo infoReader m denv dispatchSlot))
 
                     match overrides |> List.filter (IsPartialMatch g dispatchSlot compiledSig) with 
                     | [] -> 

src/Compiler/FSComp.txt

@@ -1730,4 +1730,4 @@ featureUnmanagedConstraintCsharpInterop,"Interop between C#'s and F#'s unmanaged
 3584,tcDotLambdaAtNotSupportedExpression,"Shorthand lambda syntax is only supported for atomic expressions, such as method, property, field or indexer on the implied '_' argument. For example: 'let f = _.Length'."
 3855,tcNoStaticMemberFoundForOverride,"No static abstract member was found that corresponds to this override"
 3859,tcNoStaticPropertyFoundForOverride,"No static abstract property was found that corresponds to this override"
-3860,chkStaticMembersOnObjectExpressions,"Static members are not allowed in object expressions."
+3860,chkStaticMembersOnObjectExpressions,"Object expressions cannot implement interfaces with static abstract members or declare static members."