Comment by achierius
Some huge percentage of that is just drivers. The kernel is likely what would be of interest to someone in this regard; moreover, much of that is architecture specific. IIRC the x86 kernel is <1M lines, though probably not <1M tokens.
The AMDGPU driver alone is 5 million lines - out of about 37 million lines total. Over 10% of the codebase is a driver for a single vendor, although most of it is auto generated per-product headers.