Add getAdditionalEntries to IClasspathContributor

Adds a new method to allow classpath contributor to append additional
classpath entries at the end of the calculation process.

Author: steffenschmitt1

ui/org.eclipse.pde.core/src/org/eclipse/pde/core/IClasspathContributor.java

@@ -68,4 +68,24 @@ public interface IClasspathContributor {
 	 * @return additional classpath entries to add to the project, possibly empty, must not be <code>null</code>
 	 */
 	List<IClasspathEntry> getEntriesForDependency(BundleDescription project, BundleDescription addedDependency);
+
+	/**
+	 * Get any additional classpath entries to add to a project when its
+	 * classpath is first computed. The provided {@link BundleDescription}
+	 * describes the plug-in project that the classpath is being computed for.
+	 * The entries are added at the end of the calculation process. Additional
+	 * PDE model information can be obtained using
+	 * {@link PluginRegistry#findModel(Resource)}.
+	 *
+	 * @param project
+	 *            the bundle descriptor for the plug-in project having its
+	 *            classpath computed
+	 * @return additional classpath entries to add to the project at the end of
+	 *         the classpath calculation, possibly empty, must not be
+	 *         <code>null</code>
+	 * @since 3.21
+	 */
+	default List<IClasspathEntry> getAdditionalEntries(BundleDescription project) {
+		return List.of();
+	}
 }

ui/org.eclipse.pde.core/src/org/eclipse/pde/internal/core/RequiredPluginsClasspathContainer.java

@@ -276,6 +276,10 @@ private List<IClasspathEntry> computePluginEntriesByModel() {
 
 			addJunit5RuntimeDependencies(added, entries);
 
+			// Add any additional library entries contributed via classpath
+			// contributor
+			getClasspathContributors().forEach(cc -> entries.addAll(cc.getAdditionalEntries(desc)));
+
 		} catch (CoreException e) {
 		}
 		return entries;