buf0lru.c: Always #include "srv0srv.h"
buf_block_get_lock_mutex(), buf_frame_get_lock_mutex(): Remove.
mtr0log.ic: Remove #include "page0page.h" and replace the page_
functions with lower-level ones to break an #include cycle.
dict0dict.ic: Remove unnecessary #include "trx0undo.h" and "trx0sys.h"
that would create an #include cycle.
Replace buf_frame_t* guess with buf_block_t* guess in order to avoid
a buf_block_align() call.
trx_undo_t: Replace page_t* guess_page with buf_block_t* guess_block.
btr_search_t: Replace page_t* root_guess with buf_block_t* root_guess.
btr_cur_t: Move page_block to page_cur_t::block.
page_cur_get_block(), page_cur_get_page_zip(): New functions.
page_cur_position(): Add parameter block.
Remove many page_zip parameters, now that there is page_cur_get_page_zip().
Replace some page, page_zip parameters with block.
Add some const qualifiers to function parameters and remove casts.
PAGE_HEAP_NO_INFIMUM, PAGE_HEAP_NO_SUPREMUM, PAGE_HEAP_NO_USER_LOW:
New constants.
Replace some cursor code in low-level diagnostic functions with
direct management of rec, because buf_block_t::buf_fix_count may be 0
when the functions are called, and debug assertions would fail.
with page_get_page_no() and page_get_space_id(). We want to avoid
buf_block_align() calls, and the page_no and space_id are now stamped
on the pages early on.