Kernel addresses not in agreement with "kernel" code model

Currently, the kernel target spec JSON specifies "code-model": "kernel". However, as per the System V ABI (https://gitlab.com/x86-psABIs/x86-64-ABI), that code model requires all symbols to be in the range 2^64 - 2^31 .. 2^64 - 2^24 (0xFFFF_FFFF_8000_0000..0xFFFF_FFFF_FF00_0000, 2032 MiB), whereas the kernel currently resides at 2^64 - 2^40 .. 2^64 - 2^39 (0xFFFF_FF00_0000_0000..0xFFFF_FF80_0000_0000, 510th PML4e counting from zero).

That said, we might want KASLR though (at least allow enabling it), in which case a more suitable code model might be the "small position independent code model" (AFAIK), also limiting the kernel size to 2032 MiB (three orders of magnitude more than the current kernel size of approximately 1 MiB).