added xmlMallocAtomic() to be used when allocating blocks which do not

* DOCBparser.c HTMLparser.c c14n.c catalog.c encoding.c globals.c
  nanohttp.c parser.c parserInternals.c relaxng.c tree.c uri.c
  xmlmemory.c xmlreader.c xmlregexp.c xpath.c xpointer.c
  include/libxml/globals.h include/libxml/xmlmemory.h: added
  xmlMallocAtomic() to be used when allocating blocks which
  do not contains pointers, add xmlGcMemSetup() and xmlGcMemGet()
  to allow registering the full set of functions needed by
  a garbage collecting allocator like libgc, ref #109944
Daniel
diff --git a/c14n.c b/c14n.c
index cd410cc..89589ca 100644
--- a/c14n.c
+++ b/c14n.c
@@ -1854,7 +1854,7 @@
      * allocate an translation buffer.
      */
     buffer_size = 1000;
-    buffer = (xmlChar *) xmlMalloc(buffer_size * sizeof(xmlChar));
+    buffer = (xmlChar *) xmlMallocAtomic(buffer_size * sizeof(xmlChar));
     if (buffer == NULL) {
         xmlGenericError(xmlGenericErrorContext, "malloc failed");
         return (NULL);