MDEV-20985 Add LEX methods stmt_drop_{function|procedure}() and stmt_alter_{function|procedure}_start()

Adding a few helper LEX methods,
to unify sql_yacc.yy and sql_yacc_ora.yy easier

This is a logically better position.
Also, this makes the code in sql_yacc.yy and sql_yacc_ora.yy look more similar.

Something was wrong with the removal of pointer indirection,
because on 32-bit Windows we got crash recovery failures.
Curiously, WITH_ASAN of a 32-bit debug build did not notice anything.

This reverts a part of commit b7fc2c89.

We have a 2MiB recv_sys.buf for the initial buffering. The minimum size
of log_sys.buf would be 16MiB, and that buffer should be practically
unused during recovery. If the buffer pool size is measured in gigabytes,
it would indeed make sense to use the buffer pool for the recovered log
records, perhaps after we have run out of log_sys.buf.

FIXME: allow the entire buf_block_t::frame to be used for buffered
log records, and remove MEM_HEAP_FOR_RECV_SYS. For example, use
buf_page_t::list or buf_page_t::LRU for keeping track of memory that
was allocated for recovery? Most members of buf_block_t
(except buf_block_t::frame) are unused when
block->page.state == BUF_BLOCK_MEMORY.

Follow-up to commit 8965ae27:
always initialize found_group.

recv_t, recv_t::data_t: Define constructors that copy the log records

Ideally, we should remove recv_sys.buf, RECV_DATA_BLOCK_SIZE,
and recv_sys_justify_left_parsing_buf(), and let the
recv_sys.pages point directly to a buffer of parsed redo log
records.

The RECV_PARSING_BUF_SIZE (size of recv_sys.buf) is only 2MiB,
while the minimum innodb_log_buffer_size (size of log_sys.buf) is 16MiB,
and log_sys.buf is unused during redo log apply!

Except for fil_name_process(), which invokes os_normalize_path(),
the redo log record parser will not modify the redo log records.
Add const qualifiers accordingly.

followup to 00c3a288

storage/innobase/log/log0recv.cc|1760 col 35 error| 'void* memcpy(void*, const void*, size_t)' writing to an object of type 'struct recv_t' with no trivial copy-assignment [-Werror=class-memaccess]

This reverts commit dacd1794.

- Add SLEEP() calls to the testcase to make it really test that the
  time doesn't change.
- Always use .frm file creation time as a creation timestamp (attempts
  to re-use older create_time when the table DDL changes are not good
  because then create_time will change after server restart)
- Use the same method names as the upstream patch does
- Use std::atomic for m_update_time

GCC 4.7 only knows about std::map::insert(), not emplace().

Also, reformat the function in the common style.

wsrep_init_provider_status_variables(): Always set wsrep_inited
to ensure that the memory will be freed.

The initial patch was provided by Julius Goryavsky.

page_recv_t: Replaces recv_sys_t::recs_t.
page_recv_t::state is not private, even though some accessors exist.

page_recv_t::log: A singly-linked list of log_rec_t* with STL decoration
and the custom operations trim() and append(). The list members are private.

recv_t::data_t: Replaces recv_data_t.

recv_t::data: Remove the pointer indirection for the first log chunk,
and copy the first chunk directly after the record. Adjust the
definition of RECV_DATA_BLOCK_SIZE accordingly.

In the collections of Standard Template Library,
empty() is a predicate and clear() empties a collection.
Let us rename recv_sys.empty() to recv_sys.clear() to avoid confusion.

Variant#5 of the patch:
- take creation date from the .frm file, like InnoDB does
- Update_time is in-memory only (like in InnoDB).

innobase_drop_foreign_try(): Don't evict and reload the dict_foreign_t
during instant ALTER TABLE if the FOREIGN KEY constraint is being
dropped.

The MDEV-19630 fix (commit 07b1a26c)
was incomplete, because it did not cover a case where the
FOREIGN KEY constraint is being dropped.

MDEV-18244 Server crashes in ha_innobase::update_thd / ... / ha_partition::update_next_auto_inc_val.

Partition table with the AUTO_INCREMENT column we ahve to check if the
max value is properly loaded. So we need to open all tables in INSERT
PARTITION statement if necessary. Also we need to check if some
tables are pruned away and not count the max autoincrement in this case.

Variant#5 of the patch:
- take creation date from the .frm file, like InnoDB does
- Update_time is in-memory only (like in InnoDB).

Temporarily revert the patch

simplify type naming (less boilerplate code).
don't force a plugin to specify the name twice.

typos, comments

doubles in scientific notation with a big integer part.

In commit d1e6b0bc
some code was supposed to be modified, but instead
it got duplicated. Remove the duplicated copy.

* use compile_time_assert instead of DBUG_ASSERT

* don't use thd->clear_error(), because
  * the error was already consumed by the error handler, so there is
     nothing to clear
  * it's dangerous to clear errors indiscriminately, if the error came
    from outside of read_statistics_for_tables() it must not be cleared

mysql_insert() first opens all affected tables (which implicitly
starts a transaction in InnoDB), then stat tables.
A failure to open a stat table caused open_tables() to abort
the current stmt transaction (trans_rollback_stmt()). So, from the
server point of view the following ha_write_row()-s happened outside
of a transactions, and the server didn't bother to commit them.

The server has a mechanism to prevent a transaction being
unexpectedly committed or rolled back in the middle of a statement -
if an operation takes place _in a sub-statement_ it cannot change
the transaction state. Operations on stat tables are exactly that -
they are not allowed to change a transaction state. Put them in
a sub-statement to make sure they don't.