Modify ant target -compile-classes

Here 'modulesourcepath' attribute specifies the location of the input source
files for multi module compilation.

This patches the native Java modules: java.base and java.logging

- For gov.nasa.jpf to be able to reference the package java.base/sun.net.www.protocol.http

      --add-exports java.base/sun.net.www.protocol.http=ALL-UNNAMED

      This fixes the error:
      [javac] classes/gov.nasa.jpf/gov/nasa/jpf/CachedROHttpConnection.java:
              error: package sun.net.www.protocol.http is not visible
      [javac] (package sun.net.www.protocol.http is declared in module java.base, which does not export it to unanmed module)

- For java.base to be able to reference classes from the unnamed module (here in our case the package gov.nasa.jpf.annotation)

      --add-reads java.base=ALL-UNNAMED

      This fixes the error:

      [javac] classes/modules/java.base/java/lang/Thread.java:
              error: package gov.nasa.jpf.annotation does not exist

      [javac] classes/modules/java.base/java/io/OutputStreamWriter.java:
              error: package gov.nasa.jpf.vm does not exist

JPF code except for the java model classes is compiled into the default unnamed module.

build.xml

@@ -112,13 +112,35 @@
 
   <target name="-compile-classes" if="have_classes" depends="-compile-annotations,-compile-main" >
     <mkdir dir="build/classes"/>
-    <javac srcdir="src/classes" destdir="build/classes" includeantruntime="false"
-           debug="${debug}" deprecation="${deprecation}">
+
+    <!-- compile non-module classes -->
+    <javac srcdir="src/classes/gov:src/classes/org" destdir="build/classes" includeantruntime="false"
+           debug="${debug}" deprecation="${deprecation}" classpathref="lib.path">
       <compilerarg value="-Xlint:all"/>
-      <classpath>
-        <path refid="lib.path"/>
-        <pathelement location="build/annotations"/>
-      </classpath>
+
+      <compilerarg value="--patch-module"/>
+      <compilerarg value="java.base=src/classes/modules/java.base"/>
+
+      <compilerarg value="--patch-module"/>
+      <compilerarg value="java.logging=src/classes/modules/java.logging"/>
+
+      <compilerarg value="--add-exports"/>
+      <compilerarg value="java.base/sun.net.www.protocol.http=ALL-UNNAMED"/>
+
+      <compilerarg value="--add-reads"/>
+      <compilerarg value="java.base=ALL-UNNAMED"/>
+    </javac>
+
+    <!-- patch model classes -->
+    <javac modulesourcepath="src/classes/modules" destdir="build/classes" includeantruntime="false"
+           debug="${debug}" deprecation="${deprecation}" classpathref="lib.path">
+      <compilerarg value="-Xlint:all"/>
+
+      <compilerarg value="--patch-module"/>
+      <compilerarg value="java.base=src/classes/modules/java.base"/>
+
+      <compilerarg value="--patch-module"/>
+      <compilerarg value="java.logging=src/classes/modules/java.logging"/>
     </javac>
   </target>