Undo last change, it broke ports and is not strictly speaking part of the fix for bug 253241.

js/src/jsprf.c

@@ -55,7 +55,7 @@
 ** and requires array notation.
 */
 #ifdef HAVE_VA_COPY
-#define VARARGS_ASSIGN(foo, bar)        va_copy(foo,bar)
+#define VARARGS_ASSIGN(foo, bar)        VA_COPY(foo,bar)
 #elif defined(HAVE_VA_LIST_AS_ARRAY)
 #define VARARGS_ASSIGN(foo, bar)        foo[0] = bar[0]
 #else