git: openjdk/jdk-sandbox: json: Improve exception messages. Document NPE for member()

[duke]

Changeset: aa77addb
Branch: json
Author:    Justin Lu <justin.lu at oracle.com>
Date:      2025-08-08 14:09:22 +0000
URL:       https://git.openjdk.org/jdk-sandbox/commit/aa77addbe27552bf3f59ba166ca693edf3a59a6d

Improve exception messages. Document NPE for member()

! src/java.base/share/classes/java/util/json/JsonArray.java
! src/java.base/share/classes/java/util/json/JsonObject.java
! src/java.base/share/classes/java/util/json/JsonValue.java
! src/java.base/share/classes/jdk/internal/util/json/Utils.java
! test/jdk/java/util/json/TestAssertion.java