Do not include default sanitizer blacklists into -M/-MM/-MD/-MMD output.
Introduce a frontend option -fdepfile-entry, and only insert them
for the user-defined sanitizer blacklists. In frontend, grab ExtraDeps
from -fdepfile-entry, instead of -fsanitize-blacklist.
Maybe use FileCheck -implicit-check-not= to verify that this doesn't also appear on the other side of the -fsanitize-blacklist?