Bump Roslyn version to 2.8.0
Bump Roslyn version to 2.8.0

(cherry picked from commit db39d7e0e0280567fef5734c5571290e3673ae47)
(cherry picked from commit 0c7d7d2e1de0fac3b7457087b2ddbd2c1f3247ea)

aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore