Function xsltExtModuleFunctionLookup 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn xsltExtModuleFunctionLookup(
    name: *const xmlChar,
    URI: *const xmlChar,
) -> Option<xmlXPathFunction>

xsltExtModuleFunctionLookup (extensions.c): global function lookup.

UPSTREAM-PARITY

xmlXPathFunction xsltExtModuleFunctionLookup(const xmlChar *name,
                                             const xmlChar *URI);