Add gen6+ fixed ability hot path

Closes #2135

PKHeX.Core/Legality/Encounters/Generator/EncounterStaticGenerator.cs

@@ -243,6 +243,7 @@ namespace PKHeX.Core
                 Location = Transfer1,
                 EggLocation = 0,
                 Level = pkmMetLevel,
+                Generation = 7,
                 Version = GameVersion.RBY
             };
             enc.FlawlessIVCount = enc.Fateful ? 5 : 3;
@@ -261,6 +262,7 @@ namespace PKHeX.Core
                 Location = Transfer2,
                 EggLocation = 0,
                 Level = pkmMetLevel,
+                Generation = 7,
                 Version = GameVersion.GSC
             };
             enc.FlawlessIVCount = enc.Fateful ? 5 : 3;

PKHeX.Core/Legality/Verifiers/AbilityVerifier.cs

@@ -91,6 +91,15 @@ namespace PKHeX.Core
         private CheckResult VerifyFixedAbility(LegalityAnalysis data, IReadOnlyList<int> abilities, AbilityState state, int EncounterAbility, int abilval)
         {
             var pkm = data.pkm;
+            if (data.Info.EncounterMatch is IGeneration g && g.Generation >= 6)
+            {
+                if (IsAbilityCapsuleModified(pkm, abilities, EncounterAbility))
+                    return GetValid(LAbilityCapsuleUsed);
+                if (pkm.AbilityNumber != EncounterAbility)
+                    return INVALID;
+                return VALID;
+            }
+
             if ((pkm.AbilityNumber == 4) != (EncounterAbility == 4))
                 return GetInvalid(LAbilityHiddenFail);