Merge new release of InnoDB 5.7.30 to 10.2

MySQL 5.7.30 includes the following InnoDB changes:

Not applicable to MariaDB Server

Bug #29448406 TRX_UNDO_REC_COPY NEEDLESSLY RELIES ON BUFFER POOL PAGE ALIGNMENT
MDEV-22388 was filed for handling undo log corruption in a better way. The change in MySQL 5.7.30 only seems to slightly change the way how corruption is reported. The server would still crash on a corrupted undo log record even after those changes.

Bug #30355485 CRASH WHEN DOING ANY OPERATION ON SUB-PARTITIONED TABLE
Bug #29866408 SERVER CRASHES WHEN ADDING LONGTEXT COLUMN
These are specific to the partitioning refactoring in MySQL 5.7 (ha_innopart), which is not present in MariaDB Server.

Bug #20644698 INNODB TABLESPACE IMPORT FAILS WHEN IMPORTING TABLE W/ DIFFERENT DATA DIRECTORY
This is a follow-up to a MySQL 5.7.29 change that we rejected in MDEV-21499.

Bug#30190199 - ERROR WHEN IMPORTING TABLESPACE WITH DIFFERENT DATA DIRECTORY LACKS DETAILS
Ever since MDEV-12488, MariaDB already ignores any mismatch of a DATA DIRECTORY clause when importing tablespaces. The flag in .ibd files is basically treated as garbage, because it does not affect the format of the data file in any way. The MySQL fix will refuse such import, but slightly improve the error message. Our error messages were improved in MDEV-16851.

We will ignore such differences to avoid unnecessary inconvenience to the user. The contents of a .ibd file does not depend on the file name.

BUG##30787535 : FULLTEXT INDEX TABLES CREATED IN ENCRYPTED SCHEMA ARE NOT ENCRYPTED
This affects the InnoDB encryption that was introduced in MySQL 5.7 and predated by innodb_encrypt_tables in MariaDB 10.1. In MariaDB, pars_create_table() would invoke tab_create_graph_create() with the additional parameters FIL_ENCRYPTION_DEFAULT, FIL_DEFAULT_ENCRYPTION_KEY, which would allow the internal tables for FULLTEXT INDEX to be encrypted if innodb_encrypt_tables is set.

Bug #29465567 INNODB: RTREE SPLIT ASSERTION FAILURE
This (initially filed as MDEV-22389) turned out to be a duplicate of MDEV-13942.

Applicable to MariaDB Server

Bug#30437378 : ASSERTION N_EXT == DTUPLE->GET_N_EXT() AT REC_GET_CONVERTED_SIZE() IN REM0REC.IC
Filed as MDEV-22384 (a follow-up of MDEV-21511).

Bug#30405531 : I_INNODB_ZIP.BUG16067973 FAILS ON UBSAN WEEKLY-TRUNK
Filed as MDEV-22392.

Bug #29717909 MEMORY LIFETIME OF VARIABLES BETWEEN CHECK AND UPDATE INCORRECTLY MANAGED
Filed as MDEV-22393.