undid last change (my bad). Put necessary fix in libxslt/libexslt instead.

* include/libxml/xpathInternals.h: undid last change (my
  bad).  Put necessary fix in libxslt/libexslt instead.
* include/libxml/DOCBparser.h: put test for __GCC__ on
  warning directive (Bug 129105)
3 files changed