Revise Javadoc and release notes regarding void lookups

See #4048

Author: sbrannen

documentation/src/docs/asciidoc/release-notes/release-notes-5.12.0-M1.adoc

@@ -42,8 +42,10 @@ JUnit repository on GitHub.
   `addClassContainerSelectorResolver()`.
 * Introduce `ReflectionSupport.makeAccessible(Field)` for third-party use rather than
   calling the internal `ReflectionUtils.makeAccessible(Field)` method directly.
-* Support both the primitive type `void` and the wrapper type `Void` in the internal
-  `ReflectionUtils` to allow `String` to `Class` conversion in parameterized tests.
+* The `ReflectionSupport.tryToLoadClass(...)` utility methods now support lookups for the
+  `"void"` pseudo-type, which indirectly supports `String` to `Class` conversion for
+  `"void"` in parameterized tests in JUnit Jupiter.
+* `ReflectionUtils` now treats `Void` as a _wrapper_ type for the `void` pseudo-type.
 * New `--exclude-methodname` and `--include-methodname` options added to the
   `ConsoleLauncher` to include or exclude methods based on fully qualified method names
   without parameters. For example, `--exclude-methodname=^org\.example\..+#methodname`

junit-platform-commons/src/main/java/org/junit/platform/commons/util/ReflectionUtils.java

@@ -418,9 +418,9 @@ public static boolean isMultidimensionalArray(Object obj) {
 	 * supplied target type for the purpose of reflective method invocations.
 	 *
 	 * <p>In contrast to {@link Class#isAssignableFrom(Class)}, this method
-	 * returns {@code true} if the target type represents a primitive type whose
-	 * wrapper matches the supplied source type. In addition, this method
-	 * also supports
+	 * returns {@code true} if the target type represents a primitive type (or
+	 * {@code void}) whose wrapper matches the supplied source type. In addition,
+	 * this method also supports
 	 * <a href="https://docs.oracle.com/javase/specs/jls/se8/html/jls-5.html#jls-5.1.2">
 	 * widening conversions</a> for primitive target types.
 	 *
@@ -454,8 +454,8 @@ public static boolean isAssignableTo(Class<?> sourceType, Class<?> targetType) {
 	 * type for the purpose of reflective method invocations.
 	 *
 	 * <p>In contrast to {@link Class#isInstance(Object)}, this method returns
-	 * {@code true} if the target type represents a primitive type whose
-	 * wrapper matches the supplied object's type. In addition, this method
+	 * {@code true} if the target type represents a primitive type (or {@code void})
+	 * whose wrapper matches the supplied object's type. In addition, this method
 	 * also supports
 	 * <a href="https://docs.oracle.com/javase/specs/jls/se8/html/jls-5.html#jls-5.1.2">
 	 * widening conversions</a> for primitive types and their corresponding
@@ -550,11 +550,12 @@ static boolean isWideningConversion(Class<?> sourceType, Class<?> targetType) {
 	}
 
 	/**
-	 * Get the wrapper type for the supplied primitive type.
+	 * Get the wrapper type for the supplied primitive type (or {@code void}).
 	 *
-	 * @param type the primitive type for which to retrieve the wrapper type
+	 * @param type the primitive type (or {@code void}) for which to retrieve the
+	 * wrapper type
 	 * @return the corresponding wrapper type or {@code null} if the
-	 * supplied type is {@code null} or not a primitive type
+	 * supplied type is {@code null} or not a primitive type or {@code void}
 	 */
 	public static Class<?> getWrapperType(Class<?> type) {
 		return primitiveToWrapperMap.get(type);