assignContextualParameterTypes handles arguments object

Previously, it would crash — the arguments object is a transient
symbol with no declaration, and `getEffectiveTypeAnnotationNode`
does not accept `undefined`.

Author: sandersn

src/compiler/checker.ts

@@ -16665,8 +16665,9 @@ namespace ts {
                 }
             }
             if (signature.hasRestParameter && isRestParameterIndex(context, signature.parameters.length - 1)) {
+                // parameter might be a transient symbol generated by use of `arguments` in the function body.
                 const parameter = lastOrUndefined(signature.parameters);
-                if (!getEffectiveTypeAnnotationNode(<ParameterDeclaration>parameter.valueDeclaration)) {
+                if (isTransientSymbol(parameter) || !getEffectiveTypeAnnotationNode(<ParameterDeclaration>parameter.valueDeclaration)) {
                     const contextualParameterType = getTypeOfSymbol(lastOrUndefined(context.parameters));
                     assignTypeToParameterAndFixTypeParameters(parameter, contextualParameterType);
                 }