cmd/compile: crash the compiler if trying to pass a SSA generic value of different sizes into each other

[Jorropo]

go version go1.27-devel_35e6f583ff Fri Jun 5 19:04:53 2026 -0700 linux/amd64

As in we should crash the compiler when trying to do things like this: (And64 x (Const32 [-1]))

This would make sure bugs like #79874 never escape us again.

[gopherbot]

Change https://go.dev/cl/787820 mentions this issue: cmd/compile/internal/ssa: check used const op sizes

[gabyhelp]

Related Code Changes

• cmd/compile/internal/ssa: check generic op result sizes

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}