Update gitignore for VS2015 Update 2 and later
Update gitignore for VS2015 Update 2 and later

*.VC.db files are new starting with Visual Studio 2015 Update 2. They
should not be committed to the repo.

GPUOpen-LibrariesAndSDKs/DepthBoundsTest11,GPUOpen-LibrariesAndSDKs/DepthBoundsTest11