10.1 is merged into 10.2 now. Two issues are left to fix:
(1) encryption.innochecksum test
(2) read_page0 vs page_0_crypt_read

(1) innochecksum tool did not compile after merge because
buf_page_is_corrupted uses fil_crypt_t that has been changed.

extra/CMakeLists.txt: Added fil/fil0crypt.cc as dependency
as we need to use fil_crypt_verify_checksum for encrypted pages.

innochecksum.cc: If we think page is encrypted i.e.
FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION != 0 we call
fil_crypt_verify_checksum() function to compare calculated
checksum to stored checksum calculated after encryption
(this is stored on different offset i.e.
FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION + 4).
If checksum does not match we call normal buf_page_is_corrupted
to compare calculated checksum to stored checksum.

fil0crypt.cc: add #ifdef UNIV_INNOCHECKSUM to be able to compile
this file for innochecksum tool.

(2) read_page0 is not needed and thus removed.