ntoa: fix comment disparaging gcc for not implementing C99 compound literals in C++

C99's "{ 0 }" notation for filling in a struct with all zeros was not
included in the C++11 standard, so gcc doesn't implement it and neither
does clang.

gcc does (did?) have issues with warnings on the same code in C99,
complaining about uninitialized struct members when "{0}" explicitly
initializes every member to a zero value.  These issues don't apply in
the C++ code where NTOA_TABLE_ENTRY_END is used.

Signed-off-by: Zygo Blaxell <bees@furryterror.org>

include/crucible/ntoa.h

@@ -22,7 +22,7 @@ namespace crucible {
 // Enumerations (entire value matches all bits)
 #define NTOA_TABLE_ENTRY_ENUM(x) { .n = (x), .mask = ~0UL,  .a = (#x) }
 
-// End of table (sorry, gcc doesn't implement this)
+// End of table (sorry, C++ didn't get C99's compound literals, so we have to write out all the member names)
 #define NTOA_TABLE_ENTRY_END() { .n = 0, .mask = 0, .a = nullptr }
 
 #endif // CRUCIBLE_NTOA_H