scmutil.addremove: pull ui.status printing out of the loop This will let us stop sorting all the results in an upcoming patch. This also permits future refactorings where the same code consumes dirstate.walk results but doesn't print anything out. An argument could be made that printing out results as we go along is more responsive UI-wise. However, at this point iterating through walk results is actually faster than sorting them, so once we stop sorting all the results the argument ceases to be valid.

scmutil.addremove: remove redundant directory and symlink checks dirstate.walk only does lstats and never returns stat objects for directories. On a large repository with 170,000 files, this speeds perfaddremove up from 2.40 seconds to 2.34.