Introduce experimental -Xuse-javac compilation mode

In this mode, javac AST and Symbol files are used during
Kotlin compilation instead of PSI / binary stuff.
Later, they are reused for Java file compilation.
javac in this mode is integrated into kotlinc.

compiler/frontend.java/frontend.java.iml

@@ -11,5 +11,6 @@
     <orderEntry type="library" scope="PROVIDED" name="intellij-core" level="project" />
     <orderEntry type="module" module-name="descriptor.loader.java" exported="" />
     <orderEntry type="module" module-name="util" />
+    <orderEntry type="module" module-name="javac-wrapper" />
   </component>
 </module>