WIP: bin format improvements

- Remove linear lookups
- Enable output of relocations in the map file
- Other performance fixes

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>

include/nasmlib.h

@@ -334,6 +334,11 @@ static inline const char *nasm_digit_chars(bool ucase)
  */
 int32_t seg_alloc(void);
 
+/*
+ * Return the lowest unused segment index, suitable for array sizing.
+ */
+int32_t seg_maxindex(void);
+
 /*
  * Add/replace or remove an extension to the end of a filename
  */