Martin von Zweigbergk <martinvonz@google.com> [Tue, 05 Feb 2019 14:42:13 -0800] rev 41594
largefiles: use wrappedfunction() for match() override in overridecopy()
This reduced the time that the override is in place, but I that it's
correct this way (only for the duration of the orig() call).
Differential Revision: https://phab.mercurial-scm.org/D5867