C#, Java, and Swift targets were manually collecting compiler arguments
rather than using the helper function for this purpose. This caused each
target type to add arguments in a different order, and to forget to add
some arguments respectively:
C#: /nologo, -warnaserror
Java: warning level (-nowarn, -Xlint:all, -Xdoclint:all), debug arguments
(-g, -g:none), -Werror
Swift: -warnings-as-errors
Fix this. Also fix up some no-longer-unused argument processing in the
Compiler implementations.