NormalizeObjectFromLegacySDK should handle marks

Make sure that this function can handle any unexpectedly marked values.
The only remaining caller of this function is in the diff formatter,
which uses it to suppress meaningless diffs created by legacy providers.

plans/objchange/normalize_obj.go

@@ -19,6 +19,12 @@ import (
 // okay because type consistency is enforced when deserializing the value
 // returned from the provider over the RPC wire protocol anyway.
 func NormalizeObjectFromLegacySDK(val cty.Value, schema *configschema.Block) cty.Value {
+	val, valMarks := val.UnmarkDeepWithPaths()
+	val = normalizeObjectFromLegacySDK(val, schema)
+	return val.MarkWithPaths(valMarks)
+}
+
+func normalizeObjectFromLegacySDK(val cty.Value, schema *configschema.Block) cty.Value {
 	if val == cty.NilVal || val.IsNull() {
 		// This should never happen in reasonable use, but we'll allow it
 		// and normalize to a null of the expected type rather than panicking
@@ -50,7 +56,7 @@ func NormalizeObjectFromLegacySDK(val cty.Value, schema *configschema.Block) cty
 				if lv.IsNull() && blockS.Nesting == configschema.NestingGroup {
 					vals[name] = blockS.EmptyValue()
 				} else {
-					vals[name] = NormalizeObjectFromLegacySDK(lv, &blockS.Block)
+					vals[name] = normalizeObjectFromLegacySDK(lv, &blockS.Block)
 				}
 			} else {
 				vals[name] = unknownBlockStub(&blockS.Block)
@@ -65,7 +71,7 @@ func NormalizeObjectFromLegacySDK(val cty.Value, schema *configschema.Block) cty
 				subVals := make([]cty.Value, 0, lv.LengthInt())
 				for it := lv.ElementIterator(); it.Next(); {
 					_, subVal := it.Element()
-					subVals = append(subVals, NormalizeObjectFromLegacySDK(subVal, &blockS.Block))
+					subVals = append(subVals, normalizeObjectFromLegacySDK(subVal, &blockS.Block))
 				}
 				vals[name] = cty.ListVal(subVals)
 			}
@@ -79,7 +85,7 @@ func NormalizeObjectFromLegacySDK(val cty.Value, schema *configschema.Block) cty
 				subVals := make([]cty.Value, 0, lv.LengthInt())
 				for it := lv.ElementIterator(); it.Next(); {
 					_, subVal := it.Element()
-					subVals = append(subVals, NormalizeObjectFromLegacySDK(subVal, &blockS.Block))
+					subVals = append(subVals, normalizeObjectFromLegacySDK(subVal, &blockS.Block))
 				}
 				vals[name] = cty.SetVal(subVals)
 			}