Remove unused enum; add comments re unity builds

ChangeLog

@@ -1,5 +1,5 @@
-Change Log for PCRE2
---------------------
+Change Log for PCRE2 - see also the Git log
+-------------------------------------------
 
 
 Version 10.41 xx-xxx-2022
@@ -16,6 +16,8 @@ pcre2test. It never would have overflowed in practice, but some casts have been
 added and at the some time there's been some tidying of fprints that output 
 size_t values.
 
+4. PR #94 showed up an unused enum in pcre2_convert.c, which is now removed. 
+
 
 Version 10.40 15-April-2022
 ---------------------------

src/pcre2_compile.c

@@ -10620,6 +10620,8 @@ re = NULL;
 goto EXIT;
 }
 
+/* These #undefs are here to enable unity builds with CMake. */
+
 #undef NLBLOCK /* Block containing newline information */
 #undef PSSTART /* Field containing processed string start */
 #undef PSEND   /* Field containing processed string end */

src/pcre2_convert.c

@@ -7,7 +7,7 @@ and semantics are as close as possible to those of the Perl 5 language.
 
                        Written by Philip Hazel
      Original API code Copyright (c) 1997-2012 University of Cambridge
-          New API code Copyright (c) 2016-2018 University of Cambridge
+          New API code Copyright (c) 2016-2022 University of Cambridge
 
 -----------------------------------------------------------------------------
 Redistribution and use in source and binary forms, with or without
@@ -65,9 +65,8 @@ POSSIBILITY OF SUCH DAMAGE.
 #define STR_QUERY_s STR_LEFT_PARENTHESIS STR_QUESTION_MARK STR_s STR_RIGHT_PARENTHESIS
 #define STR_STAR_NUL STR_LEFT_PARENTHESIS STR_ASTERISK STR_N STR_U STR_L STR_RIGHT_PARENTHESIS
 
-/* States for range and POSIX processing */
+/* States for POSIX processing */
 
-enum { RANGE_NOT_STARTED, RANGE_STARTING, RANGE_ACTIVE };
 enum { POSIX_START_REGEX, POSIX_ANCHORED, POSIX_NOT_BRACKET,
        POSIX_CLASS_NOT_STARTED, POSIX_CLASS_STARTING, POSIX_CLASS_STARTED };
 

src/pcre2_dfa_match.c

@@ -4057,6 +4057,8 @@ while (rws->next != NULL)
 return rc;
 }
 
+/* These #undefs are here to enable unity builds with CMake. */
+
 #undef NLBLOCK /* Block containing newline information */
 #undef PSSTART /* Field containing processed string start */
 #undef PSEND   /* Field containing processed string end */

src/pcre2_match.c

@@ -7533,6 +7533,8 @@ else match_data->rc = PCRE2_ERROR_NOMATCH;
 return match_data->rc;
 }
 
+/* These #undefs are here to enable unity builds with CMake. */
+
 #undef NLBLOCK /* Block containing newline information */
 #undef PSSTART /* Field containing processed string start */
 #undef PSEND   /* Field containing processed string end */