The libraries were missing from the build for AIX.
diff --git a/core/org.eclipse.cdt.core.aix/build.properties b/core/org.eclipse.cdt.core.aix/build.properties
index 5ba91ed..7ce11ac 100644
--- a/core/org.eclipse.cdt.core.aix/build.properties
+++ b/core/org.eclipse.cdt.core.aix/build.properties
@@ -13,5 +13,6 @@
                *.jar,\
                cdtaix.jar,\
                fragment.properties,\
-               about.html
+               about.html,\
+               os/
 src.includes = library/