Generate fmgr prototypes automatically

Gen_fmgrtab.pl creates a new file fmgrprotos.h, which contains
prototypes for all functions registered in pg_proc.h.  This avoids
having to manually maintain these prototypes across a random variety of
header files.  It also automatically enforces a correct function
signature, and since there are warnings about missing prototypes, it
will detect functions that are defined but not registered in
pg_proc.h (or otherwise used).

Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>

src/backend/utils/adt/ascii.c

@@ -13,6 +13,7 @@
 
 #include "mb/pg_wchar.h"
 #include "utils/ascii.h"
+#include "utils/builtins.h"
 
 static void pg_to_ascii(unsigned char *src, unsigned char *src_end,
 			unsigned char *dest, int enc);