cpluspluscheck complains about use of register

Applying: Remove uses of register due to incompatibility with C++17 and up
Using index info to reconstruct a base tree...
A	.cirrus.yml
M	src/backend/regex/regexec.c
M	src/include/port/atomics/arch-x86.h
M	src/include/storage/s_lock.h
Falling back to patching base and 3-way merge...
Auto-merging src/include/storage/s_lock.h
CONFLICT (content): Merge conflict in src/include/storage/s_lock.h
Auto-merging src/include/port/atomics/arch-x86.h
Auto-merging src/backend/regex/regexec.c
CONFLICT (modify/delete): .cirrus.yml deleted in HEAD and modified in Remove uses of register due to incompatibility with C++17 and up. Version Remove uses of register due to incompatibility with C++17 and up of .cirrus.yml left in tree.
Patch failed at 0001 Remove uses of register due to incompatibility with C++17 and up

error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config advice.mergeConflict false"