WL#5030: Split and remove mysql_priv.h

This patch:

- Moves all definitions from the mysql_priv.h file into
  header files for the component where the variable is
  defined
- Creates header files if the component lacks one
- Eliminates all include directives from mysql_priv.h
- Eliminates all circular include cycles
- Rename time.cc to sql_time.cc
- Rename mysql_priv.h to sql_priv.h

sql/sql_list.h

@@ -26,6 +26,11 @@
 
 void *sql_alloc(size_t);
 
+#include "my_sys.h"                    /* alloc_root, TRASH, MY_WME,
+                                          MY_FAE, MY_ALLOW_ZERO_PTR */
+#include "m_string.h"                           /* bfill */
+#include "thr_malloc.h"                         /* sql_alloc */
+
 /* mysql standard class memory allocator */
 
 class Sql_alloc
@@ -61,6 +66,57 @@ public:
 };
 
 
+/**
+   Struct to handle simple linked lists.
+
+   @todo What is the relation between this class and list_node, below?
+   /Matz
+
+   @see list_node, base_list, List
+
+*/
+typedef struct st_sql_list {
+  uint elements;
+  uchar *first;
+  uchar **next;
+
+  st_sql_list() {}                              /* Remove gcc warning */
+  inline void empty()
+  {
+    elements=0;
+    first=0;
+    next= &first;
+  }
+  inline void link_in_list(uchar *element,uchar **next_ptr)
+  {
+    elements++;
+    (*next)=element;
+    next= next_ptr;
+    *next=0;
+  }
+  inline void save_and_clear(struct st_sql_list *save)
+  {
+    *save= *this;
+    empty();
+  }
+  inline void push_front(struct st_sql_list *save)
+  {
+    *save->next= first;				/* link current list last */
+    first= save->first;
+    elements+= save->elements;
+  }
+  inline void push_back(struct st_sql_list *save)
+  {
+    if (save->first)
+    {
+      *next= save->first;
+      next= save->next;
+      elements+= save->elements;
+    }
+  }
+} SQL_LIST;
+
+
 /*
   Basic single linked list
   Used for item and item_buffs.
@@ -637,4 +693,7 @@ list_copy_and_replace_each_value(List<T> &list, MEM_ROOT *mem_root)
     it.replace(el->clone(mem_root));
 }
 
+void free_list(I_List <i_string_pair> *list);
+void free_list(I_List <i_string> *list);
+
 #endif // INCLUDES_MYSQL_SQL_LIST_H