tree-wide: "<n>bit" → "<n>-bit"

In some places, "<n> bits" is used when more appropriate.

src/basic/utf8.h

@@ -38,7 +38,7 @@ size_t utf16_encode_unichar(char16_t *out, char32_t c);
 char *utf16_to_utf8(const char16_t *s, size_t length /* bytes! */);
 char16_t *utf8_to_utf16(const char *s, size_t length);
 
-size_t char16_strlen(const char16_t *s); /* returns the number of 16bit words in the string (not bytes!) */
+size_t char16_strlen(const char16_t *s); /* returns the number of 16-bit words in the string (not bytes!) */
 
 int utf8_encoded_valid_unichar(const char *str, size_t length);
 int utf8_encoded_to_unichar(const char *str, char32_t *ret_unichar);