Log Message:
gcc10*: update to 10.5.0

The list of PR's fixed since 10.4.0 can be found here:

https://gcc.gnu.org/bugzilla/buglist.cgi?bug_status=RESOLVED&resolution=FIXED&target_milestone=10.5

which includes 3 C, 25 C++, 4 debug, 17 libstdc++, and many others for the
internals.