Change TABLE->alias to String for less memory reallocation

Changed some String.ptr() -> String.c_ptr() for String that are not guaranteed to end with \0
Removed some c_ptr() usage from parameters to functions that takes ptr & length
Use preallocate buffers to avoid calling malloc() for most operations. 


sql/event_db_repository.cc:
  alias is now a String
sql/event_scheduler.cc:
  c_ptr -> c_ptr_safe() to avoid warnings from valgrind.
sql/events.cc:
  c_ptr -> c_ptr_safe() to avoid warnings from valgrind.
  c_ptr -> ptr() as function takes ptr & length
sql/field.cc:
  alias is now a String
sql/field.h:
  alias is now a String
sql/ha_partition.cc:
  alias is now a String
sql/handler.cc:
  alias is now a String
  ptr() -> c_ptr() as string is not guaranteed to be \0 terminated
sql/item.cc:
  Store error parameter in separarte buffer to ensure correct error message
sql/item_func.cc:
  ptr() -> c_ptr_safe() as string is not guaranteed to be \0 terminated
sql/item_sum.h:
  Use my_strtod() instead of my_atof() to not have to make string \0 terminated
sql/lock.cc:
  alias is now a String
sql/log.cc:
  c_ptr() -> ptr() as function takes ptr & length
sql/log_event.cc:
  c_ptr_quick() -> ptr() as we only want to get the pointer to String buffer
sql/opt_range.cc:
  ptr() -> c_ptr() as string is not guaranteed to be \0 terminated
sql/opt_table_elimination.cc:
  alias is now a String
sql/set_var.cc:
  ptr() -> c_ptr() as string is not guaranteed to be \0 terminated
  c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
  c_ptr() -> ptr() as function takes ptr & length
  Simplify some code.
sql/sp.cc:
  c_ptr() -> ptr() as function takes ptr & length
sql/sp_rcontext.cc:
  alias is now a String
sql/sql_base.cc:
  alias is now a String.
  Here we win a realloc() for most alias usage.
sql/sql_class.cc:
  Use size descriptor for printf() to avoid accessing bytes outside of buffer
sql/sql_insert.cc:
  Change allocation of TABLE as it's now contains a String
  _ptr() -> ptr() as function takes ptr & length
sql/sql_load.cc:
  Use preallocate buffers to avoid calling malloc() for most operations.
sql/sql_parse.cc:
  Use c_ptr_safe() to ensure string is \0 terminated.
sql/sql_plugin.cc:
  c_ptr_quick() -> ptr() as function takes ptr & length
sql/sql_select.cc:
  alias is now a String
sql/sql_show.cc:
  alias is now a String
sql/sql_string.h:
  Added move() function to change who owns the string (owner does the free)
sql/sql_table.cc:
  alias is now a String
  c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
sql/sql_test.cc:
  c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
  alias is now a String
sql/sql_trigger.cc:
  c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
  Use field->init() to setup pointers to alias.
sql/sql_update.cc:
  alias is now a String
sql/sql_view.cc:
  ptr() -> c_ptr_safe() as string is not guaranteed to be \0 terminated
sql/sql_yacc.yy:
  r() -> c_ptr() as string is not guaranteed to be \0 terminated
sql/table.cc:
  alias is now a String
sql/table.h:
  alias is now a String
storage/federatedx/ha_federatedx.cc:
  Remove extra 1 byte alloc that is automaticly done by strmake()
  Ensure that error message ends with \0
storage/maria/ha_maria.cc:
  alias is now a String
storage/myisam/ha_myisam.cc:
  alias is now a String

sql/opt_range.cc

@@ -11274,7 +11274,8 @@ static void print_sel_tree(PARAM *param, SEL_TREE *tree, key_map *tree_map,
   if (!tmp.length())
     tmp.append(STRING_WITH_LEN("(empty)"));
 
-  DBUG_PRINT("info", ("SEL_TREE: 0x%lx (%s)  scans: %s", (long) tree, msg, tmp.ptr()));
+  DBUG_PRINT("info", ("SEL_TREE: 0x%lx (%s)  scans: %s", (long) tree, msg,
+                      tmp.c_ptr()));
 
   DBUG_VOID_RETURN;
 }
@@ -11297,7 +11298,7 @@ static void print_ror_scans_arr(TABLE *table, const char *msg,
   }
   if (!tmp.length())
     tmp.append(STRING_WITH_LEN("(empty)"));
-  DBUG_PRINT("info", ("ROR key scans (%s): %s", msg, tmp.ptr()));
+  DBUG_PRINT("info", ("ROR key scans (%s): %s", msg, tmp.c_ptr()));
   DBUG_VOID_RETURN;
 }