swift234

[Foundation overlay] Drop redundant 'Error' in the CocoaError code names.

Note: we leave all of the old names in as deprecated (with a rename),
so that we don't actually break any existing source code. Fixes
rdar://problem/27778189.

(cherry picked from commit 394094f732f3c8b0a78236e43b8ac2a28e4f547e)