Remove left-over debug printf
Improve -v2 diagnostic message for typedef

alias is not a 1-to-1 replacement for typedef and in many cases
struct based workaround is absolutely necessry.
Change -v2 diagnostic message for volatile

Sometimes volatile was used to prevent reordering in which case
synchronized may not be applicable. Threading is tricky so better
to not propose striaghtforward solution.
Merge pull request #3830 from mihails-strasuns-sociomantic/dmd-1.x

[D1] Few changes to -v2 diagnostics