Simplify type checks for nullable

This was a hold over from earlier code when this arm was not protected by isMethodArg, causing it to need this solving complexity supported by op_Implicit conversions

src/Compiler/Checking/MethodCalls.fs

@@ -290,21 +290,8 @@ let rec AdjustRequiredTypeForTypeDirectedConversions (infoReader: InfoReader) ad
         g.int32_ty, TypeDirectedConversionUsed.Yes(warn TypeDirectedConversion.BuiltIn), None
 
     elif g.langVersion.SupportsFeature LanguageFeature.NullableOptionalInterop && isMethodArg && isNullableTy g reqdTy && not (isNullableTy g actualTy) then 
-        let reqdTy2 =
-            if isTyparTy g reqdTy then
-                let tp = destTyparTy g reqdTy 
-                match tp.Constraints |> List.choose (function TyparConstraint.CoercesTo (c, _) -> Some c | _ -> None) with
-                | [reqdTy2] when tp.Rigidity = TyparRigidity.Flexible -> reqdTy2
-                | _ -> reqdTy
-            else reqdTy
-
-        if not (isTyparTy g reqdTy2) &&
-            (not (TypeFeasiblySubsumesType 0 g infoReader.amap m reqdTy2 CanCoerce actualTy) ||
-            isTyparTy g actualTy && (let ftyvs = freeInType CollectAll reqdTy2 in ftyvs.FreeTypars.Contains(destTyparTy g actualTy))) then
+        actualTy, TypeDirectedConversionUsed.Yes(warn TypeDirectedConversion.BuiltIn), None
 
-            actualTy, TypeDirectedConversionUsed.Yes(warn TypeDirectedConversion.BuiltIn), Some (reqdTy, reqdTy2, ignore)
-        else
-            reqdTy, TypeDirectedConversionUsed.No, None
     // Adhoc based on op_Implicit, perhaps returing a new equational type constraint to 
     // eliminate articifical constrained type variables.
     elif g.langVersion.SupportsFeature LanguageFeature.AdditionalTypeDirectedConversions then