Apparently javah has changed slightly in Java 1.7. In Java 1.6, when you ran javah on GDI.java, it didn't require that PointerBuffer.class be in the classpath, even though PointerBuffer is used in some parameter lists in GDI.java. In Java 1.7, javah does require that PointerBuffer.class be in the classpath.
Fixes forthcoming shortly after testing.
Fixed in commit https://github.com/WadeWalker/jogl/commit/cd31c4f0dc7a5f5595e0ca2f0e815d3814ebd94e. Submitted pull request to Sven.
Merged Wade's commit cd31c4f0dc7a5f5595e0ca2f0e815d3814ebd94e
and generalized it 78b7732498099e1cc6bbedfa7437bb3c8955cfc5.
The latter also uses 'rootrel.build' properly.