I spent the end of 2015 and the first couple of days of 2016 porting build environment scripts to Powershell and fixing up SCons based build scripts to work with Visual Studio 2015. When doing debug builds, incremental link (.ILK) and program database (.PDB) files are generated. These are considered extra files, since they're not the actual targets (like .OBJ, .EXE, .LIB or .DLL) being built.

Read: How to remove extra build output files when using SCons.