This fixes a linker warning on Windows, and improves link times for UnrealEd.dll by a few seconds (no longer does whole program optimization.)
3> VHACD.lib(VHACD.obj) : MSIL .netmodule or module compiled with /GL found; restarting link with /LTCG; add /LTCG to the link command line to improve linker performance
3> Generating code
3> Finished generating code
#codereview james.golding
[CL 2515854 by Mike Fricker in Main branch]