new tablespaces created from now on.
btr_store_big_rec_extern_fields(): Set FIL_PAGE_TYPE to FIL_PAGE_TYPE_BLOB.
buf_page_print(): Decode FIL_PAGE_TYPE. Replace if-else with switch().
buf_page_create(): Set FIL_PAGE_PREV, FIL_PAGE_NEXT and FIL_PAGE_TYPE.
trx_sysf_create(): Set FIL_PAGE_TYPE to FIL_PAGE_TYPE_TRX_SYS.
Initialize TRX_SYS_RSEG_SPACE.
FIL_PAGE_TYPE: Document that the field cannot be relied on in older
versions of MySQL/InnoDB. Add new type codes.
ibuf_bitmap_page_init(): Document that the rest of the page is uninitialized.
ibuf_add_free_page(): Log the setting of FIL_PAGE_TYPE.
fsp_header_init(): Set FIL_PAGE_TYPE to FIL_PAGE_TYPE_FSP_HDR.
Initialize FSP_NOT_USED.
fsp_fill_free_list(): Set FIL_PAGE_TYPE to FIL_PAGE_TYPE_XDES.
fsp_alloc_seg_inode_page(): Set FIL_PAGE_TYPE to FIL_PAGE_INODE.
fseg_create_general(): Set FIL_PAGE_TYPE to FIL_PAGE_TYPE_SYS.
