Properly finalize evolving array type in getTypeAtFlowCall

Author: ahejlsberg

src/compiler/checker.ts

@@ -20360,7 +20360,7 @@ namespace ts {
                     const predicate = getTypePredicateOfSignature(signature);
                     if (predicate && (predicate.kind === TypePredicateKind.AssertsThis || predicate.kind === TypePredicateKind.AssertsIdentifier)) {
                         const flowType = getTypeAtFlowNode(flow.antecedent);
-                        const type = getTypeFromFlowType(flowType);
+                        const type = finalizeEvolvingArrayType(getTypeFromFlowType(flowType));
                         const narrowedType = predicate.type ? narrowTypeByTypePredicate(type, predicate, flow.node, /*assumeTrue*/ true) :
                             predicate.kind === TypePredicateKind.AssertsIdentifier && predicate.parameterIndex >= 0 && predicate.parameterIndex < flow.node.arguments.length ? narrowTypeByAssertion(type, flow.node.arguments[predicate.parameterIndex]) :
                             type;