[llvm] [X86] Fix 32-bit immediate assertion and convert into backend error (PR #123872)

[via llvm-commits]

abhishek-kaushik22 wrote:

Maybe the IR from #121932 could be added as test

```llvm
define dso_local i32 @main() #0 {
entry:
  %x = alloca [2147483647 x i8], align 16
  %arrayidx = getelementptr inbounds [2147483647 x i8], ptr %x, i64 0, i64 -42
  store i8 33, ptr %arrayidx, align 2
  ret i32 0
}

attributes #0 = { noinline nounwind optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
```

https://github.com/llvm/llvm-project/pull/123872