Remove unused global variables

The new clang 23 has a new warning about set-but-unused
static (internal-linkage) global variables: -Wunused-but-set-global,
which is activated in PostgreSQL builds via -Wall.  This triggers a
few warnings in PostgreSQL code.  This commit removes several such
variables that were either never used or whose last use was removed
some time ago.

For pq_init_crypto_lib, we apply the same #ifdef HAVE_CRYPTO_LOCK that
the other uses of the variable already have, so that the variable is
either fully used or fully nonexistent, depending on the
configuration, not half-way.

Reinit was already documented in a comment as dead code, and it was
removed in a later branch.  To minimize the surgery there, just add an
unused attribute to silence the warning.

Reviewed-by: Andreas Karlsson <andreas@proxel.se>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/eb013f9d-2247-444e-8815-9d17b4ce78e7%40eisentraut.org

src/backend/postmaster/postmaster.c

@@ -227,7 +227,7 @@ static pgsocket ListenSocket[MAXLISTEN];
  * the postmaster stop (rather than kill) peers and not reinitialize
  * shared data structures.  (Reinit is currently dead code, though.)
  */
-static bool Reinit = true;
+pg_attribute_unused() static bool Reinit = true;
 static int	SendStop = false;
 
 /* still more option variables */

src/backend/utils/adt/jsonpath_scan.l

@@ -25,7 +25,6 @@ static JsonPathString scanstring;
 /* Handles to the buffer that the lexer uses internally */
 static YY_BUFFER_STATE scanbufhandle;
 static char *scanbuf;
-static int	scanbuflen;
 
 static void addstring(bool init, char *s, int l);
 static void addchar(bool init, char s);
@@ -393,7 +392,6 @@ jsonpath_scanner_init(const char *str, int slen)
 	 * Make a scan buffer with special termination needed by flex.
 	 */
 
-	scanbuflen = slen;
 	scanbuf = palloc(slen + 2);
 	memcpy(scanbuf, str, slen);
 	scanbuf[slen] = scanbuf[slen + 1] = YY_END_OF_BUFFER_CHAR;

src/bin/pg_dump/pg_dump_sort.c

@@ -150,7 +150,6 @@ static const int dbObjectTypePriority[] =
 StaticAssertDecl(lengthof(dbObjectTypePriority) == (DO_SUBSCRIPTION + 1),
 				 "array length mismatch");
 
-static DumpId preDataBoundId;
 static DumpId postDataBoundId;
 
 
@@ -540,7 +539,6 @@ sortDumpableObjects(DumpableObject **objs, int numObjs,
 	 * Saving the boundary IDs in static variables is a bit grotty, but seems
 	 * better than adding them to parameter lists of subsidiary functions.
 	 */
-	preDataBoundId = preBoundaryId;
 	postDataBoundId = postBoundaryId;
 
 	ordering = (DumpableObject **) pg_malloc(numObjs * sizeof(DumpableObject *));

src/interfaces/libpq/fe-secure-openssl.c

@@ -81,7 +81,9 @@ static int	my_SSL_set_fd(PGconn *conn, int fd);
 
 
 static bool pq_init_ssl_lib = true;
+#ifdef HAVE_CRYPTO_LOCK
 static bool pq_init_crypto_lib = true;
+#endif
 
 static bool ssl_lib_initialized = false;
 
@@ -112,7 +114,9 @@ pgtls_init_library(bool do_ssl, int do_crypto)
 #endif
 
 	pq_init_ssl_lib = do_ssl;
+#ifdef HAVE_CRYPTO_LOCK
 	pq_init_crypto_lib = do_crypto;
+#endif
 }
 
 PostgresPollingStatusType