* implies that noone can use them unless they are available and
* they won't be available unless used. When new symbols are probed
* in Configure, this is the way to force them into availability.
+ *
+ * Symbols should only be here temporarily. Once they are actually used,
+ * they should be removed from here.
+ *
+ * HAS_BUILTIN_ADD_OVERFLOW
+ * HAS_BUILTIN_MUL_OVERFLOW
+ * HAS_BUILTIN_SUB_OVERFLOW
+ * HAS_LOCALECONV_L
+ * HAS_MBRLEN
+ * HAS_MBRTOWC
+ * HAS_NANOSLEEP
+ * HAS_STRTOD_L
+ * HAS_STRTOLD_L
+ * I_WCHAR
*/