selftests/bpf: Add a test case for 32-bit spill tracking

When a range check is performed on a register that was 32-bit spilled to
the stack, the IDs of the two instances of the register are the same, so
the range should also be the same.

Signed-off-by: Maxim Mikityanskiy <maxim@isovalent.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240108205209.838365-6-maxtram95@gmail.com


Signed-off-by: Alexei Starovoitov <ast@kernel.org>