Fix inconsistently defined THR_LOCK_myisam_mmap

It was pthread_mutex_t in mi_static.c and 
mysql_mutex_t in my_thr_init.c
  
Solaris linker complains about different size of the 
symbol.

include/myisam.h

@@ -260,7 +260,7 @@ extern ulong myisam_bulk_insert_tree_size, myisam_data_pointer_size;
 /* which is normally forbidden                                        */
 extern int (*myisam_test_invalid_symlink)(const char *filename);
 extern ulonglong myisam_mmap_size, myisam_mmap_used;
-extern pthread_mutex_t THR_LOCK_myisam_mmap;
+extern mysql_mutex_t THR_LOCK_myisam_mmap;
 
 	/* Prototypes for myisam-functions */
 

storage/myisam/mi_packrec.c

@@ -1502,11 +1502,11 @@ my_bool _mi_memmap_file(MI_INFO *info)
 
     if (myisam_mmap_size != SIZE_T_MAX)
     {
-      pthread_mutex_lock(&THR_LOCK_myisam_mmap);
+      mysql_mutex_lock(&THR_LOCK_myisam_mmap);
       eom= data_file_length > myisam_mmap_size - myisam_mmap_used - MEMMAP_EXTRA_MARGIN;
       if (!eom)
         myisam_mmap_used+= data_file_length + MEMMAP_EXTRA_MARGIN;
-      pthread_mutex_unlock(&THR_LOCK_myisam_mmap);
+      mysql_mutex_unlock(&THR_LOCK_myisam_mmap);
     }
     else
       eom= data_file_length > myisam_mmap_size - MEMMAP_EXTRA_MARGIN;
@@ -1522,9 +1522,9 @@ my_bool _mi_memmap_file(MI_INFO *info)
       DBUG_PRINT("warning",("File isn't extended for memmap"));
       if (myisam_mmap_size != SIZE_T_MAX)
       {
-        pthread_mutex_lock(&THR_LOCK_myisam_mmap);
+        mysql_mutex_lock(&THR_LOCK_myisam_mmap);
         myisam_mmap_used-= data_file_length + MEMMAP_EXTRA_MARGIN;
-        pthread_mutex_unlock(&THR_LOCK_myisam_mmap);
+        mysql_mutex_unlock(&THR_LOCK_myisam_mmap);
       }
       DBUG_RETURN(0);
     }
@@ -1534,9 +1534,9 @@ my_bool _mi_memmap_file(MI_INFO *info)
     {
       if (myisam_mmap_size != SIZE_T_MAX)
       {
-        pthread_mutex_lock(&THR_LOCK_myisam_mmap);
+        mysql_mutex_lock(&THR_LOCK_myisam_mmap);
         myisam_mmap_used-= data_file_length + MEMMAP_EXTRA_MARGIN;
-        pthread_mutex_unlock(&THR_LOCK_myisam_mmap);
+        mysql_mutex_unlock(&THR_LOCK_myisam_mmap);
       }
       DBUG_RETURN(0);
     }
@@ -1555,9 +1555,9 @@ void _mi_unmap_file(MI_INFO *info)
 
   if (myisam_mmap_size != SIZE_T_MAX)
   {
-    pthread_mutex_lock(&THR_LOCK_myisam_mmap);
+    mysql_mutex_lock(&THR_LOCK_myisam_mmap);
     myisam_mmap_used-= info->s->mmaped_length + MEMMAP_EXTRA_MARGIN;
-    pthread_mutex_unlock(&THR_LOCK_myisam_mmap);
+    mysql_mutex_unlock(&THR_LOCK_myisam_mmap);
   }
 }
 

storage/myisam/mi_static.c

@@ -41,7 +41,7 @@ my_off_t myisam_max_temp_length= MAX_FILE_SIZE;
 ulong    myisam_bulk_insert_tree_size=8192*1024;
 ulong    myisam_data_pointer_size=4;
 ulonglong    myisam_mmap_size= SIZE_T_MAX, myisam_mmap_used= 0;
-pthread_mutex_t  THR_LOCK_myisam_mmap;
+mysql_mutex_t  THR_LOCK_myisam_mmap;
 
 static int always_valid(const char *filename __attribute__((unused)))
 {