UseJava: add INCLUDE_MODULES argument to add_jar

Arguments are added to the dependencies list, and to the "--module-path"
passed to javac, which is only generated for adequate JDK versions.

Tests/JavaModExportImport/BuildExport/CMakeLists.txt

@@ -0,0 +1,13 @@
+project(foo Java)
+
+cmake_minimum_required(VERSION 3.10)
+set(CMAKE_VERBOSE_MAKEFILE 1)
+
+find_package(Java COMPONENTS Development)
+include(UseJava)
+
+add_jar(${PROJECT_NAME} Foo.java module-info.java)
+export_jars(
+  TARGETS ${PROJECT_NAME}
+  NAMESPACE foo::
+  FILE JavaBuildExportTestConfig.cmake)

Tests/JavaModExportImport/BuildExport/Foo.java

@@ -0,0 +1,13 @@
+package org.foo;
+
+public class Foo
+{
+  public Foo()
+  {
+  }
+
+  public void printName()
+  {
+    System.out.println("Foo");
+  }
+}

Tests/JavaModExportImport/BuildExport/module-info.java

@@ -0,0 +1,3 @@
+module mod_foo {
+    exports org.foo;
+}