Linux commit 12209993e98c5fa1855c467f22a24e3d5b8be205 was backported to
4.14, so add the reverting patch to restore zfs performance.

(cherry picked from commit 71b4b7b)

Linux commit 12209993e98c5fa1855c467f22a24e3d5b8be205 was backported to
4.19, so add the reverting patch to restore zfs performance.

(cherry picked from commit 0e6d0c1)

linux_4_{14,19}: restore __kernel_fpu_{begin,restore}

CVE-2019-11577
CVE-2019-11578
CVE-2019-11579
CVE-2019-11766
I checked the commit hashes agree with those linked from nvd.nist.gov

In Nix, each string has a context that it carries of where it
originated. Some functions like filterAttrs modify the context of its
args when doing comparisons. That is important because we use the
string context of “name” to get where a derivation was defined. This
causes some builtins like unsafeGetAttrPos to report incorrectly that
the string was set in lib/attrsets.nix and reporting that as the
source file. Using removeAttrs avoids this problem.

Fixes #63679

(cherry picked from commit 1f46aaa)
The web list of packages shows the current stable branch, so we needed
to backport this to fix that effect soonish.  The change itself seems
very safe; only one rebuild is detected: `common-updater-scripts`