Fix GCC 11 -Wmaybe-uninitialized for PLUGIN_PERFSCHEMA

init_mutex_v1_t: Stop lying that the mutex parameter is const.
GCC 11.2.0 assumes that it is and could complain about any mysql_mutex_t
being uninitialized even after mysql_mutex_init() as long as
PLUGIN_PERFSCHEMA is enabled.

init_rwlock_v1_t, init_cond_v1_t: Remove untruthful const qualifiers.

Note: init_socket_v1_t is expecting that the socket fd has already
been created before PSI_SOCKET_CALL(init_socket), and therefore that
parameter really is being treated as a pointer to const.

include/mysql/psi/psi.h

@@ -1134,7 +1134,7 @@ typedef void (*register_socket_v1_t)
   @return an instrumented mutex
 */
 typedef struct PSI_mutex* (*init_mutex_v1_t)
-  (PSI_mutex_key key, const void *identity);
+  (PSI_mutex_key key, void *identity);
 
 /**
   Mutex instrumentation destruction API.
@@ -1149,7 +1149,7 @@ typedef void (*destroy_mutex_v1_t)(struct PSI_mutex *mutex);
   @return an instrumented rwlock
 */
 typedef struct PSI_rwlock* (*init_rwlock_v1_t)
-  (PSI_rwlock_key key, const void *identity);
+  (PSI_rwlock_key key, void *identity);
 
 /**
   Rwlock instrumentation destruction API.
@@ -1164,7 +1164,7 @@ typedef void (*destroy_rwlock_v1_t)(struct PSI_rwlock *rwlock);
   @return an instrumented cond
 */
 typedef struct PSI_cond* (*init_cond_v1_t)
-  (PSI_cond_key key, const void *identity);
+  (PSI_cond_key key, void *identity);
 
 /**
   Cond instrumentation destruction API.

include/mysql/psi/psi_abi_v1.h.pp

@@ -300,13 +300,13 @@ typedef void (*register_statement_v1_t)
 typedef void (*register_socket_v1_t)
   (const char *category, struct PSI_socket_info_v1 *info, int count);
 typedef struct PSI_mutex* (*init_mutex_v1_t)
-  (PSI_mutex_key key, const void *identity);
+  (PSI_mutex_key key, void *identity);
 typedef void (*destroy_mutex_v1_t)(struct PSI_mutex *mutex);
 typedef struct PSI_rwlock* (*init_rwlock_v1_t)
-  (PSI_rwlock_key key, const void *identity);
+  (PSI_rwlock_key key, void *identity);
 typedef void (*destroy_rwlock_v1_t)(struct PSI_rwlock *rwlock);
 typedef struct PSI_cond* (*init_cond_v1_t)
-  (PSI_cond_key key, const void *identity);
+  (PSI_cond_key key, void *identity);
 typedef void (*destroy_cond_v1_t)(struct PSI_cond *cond);
 typedef struct PSI_socket* (*init_socket_v1_t)
   (PSI_socket_key key, const my_socket *fd,

mysys/psi_noop.c

@@ -86,7 +86,7 @@ static void register_socket_noop(const char *category NNN,
 }
 
 static PSI_mutex*
-init_mutex_noop(PSI_mutex_key key NNN, const void *identity NNN)
+init_mutex_noop(PSI_mutex_key key NNN, void *identity NNN)
 {
   return NULL;
 }
@@ -97,7 +97,7 @@ static void destroy_mutex_noop(PSI_mutex* mutex NNN)
 }
 
 static PSI_rwlock*
-init_rwlock_noop(PSI_rwlock_key key NNN, const void *identity NNN)
+init_rwlock_noop(PSI_rwlock_key key NNN, void *identity NNN)
 {
   return NULL;
 }
@@ -108,7 +108,7 @@ static void destroy_rwlock_noop(PSI_rwlock* rwlock NNN)
 }
 
 static PSI_cond*
-init_cond_noop(PSI_cond_key key NNN, const void *identity NNN)
+init_cond_noop(PSI_cond_key key NNN, void *identity NNN)
 {
   return NULL;
 }

storage/perfschema/pfs.cc

@@ -1496,7 +1496,7 @@ static void register_socket_v1(const char *category,
   @sa PSI_v1::init_mutex.
 */
 static PSI_mutex*
-init_mutex_v1(PSI_mutex_key key, const void *identity)
+init_mutex_v1(PSI_mutex_key key, void *identity)
 {
   INIT_BODY_V1(mutex, key, identity);
 }
@@ -1519,7 +1519,7 @@ static void destroy_mutex_v1(PSI_mutex* mutex)
   @sa PSI_v1::init_rwlock.
 */
 static PSI_rwlock*
-init_rwlock_v1(PSI_rwlock_key key, const void *identity)
+init_rwlock_v1(PSI_rwlock_key key, void *identity)
 {
   INIT_BODY_V1(rwlock, key, identity);
 }
@@ -1542,7 +1542,7 @@ static void destroy_rwlock_v1(PSI_rwlock* rwlock)
   @sa PSI_v1::init_cond.
 */
 static PSI_cond*
-init_cond_v1(PSI_cond_key key, const void *identity)
+init_cond_v1(PSI_cond_key key, void *identity)
 {
   INIT_BODY_V1(cond, key, identity);
 }