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

[Matt Arsenault via llvm-commits]

================
@@ -0,0 +1,40 @@
+; RUN: not llc < %s -mtriple=i686 2>&1 | FileCheck %s -check-prefix=i686
+; RUN: llc < %s -mtriple=x86_64 | FileCheck %s -check-prefix=x86_64
+
+define dso_local i32 @main() #0 {
+; i686: error: <unknown>:0:0: requesting 64-bit offset in 32-bit immediate: main
----------------
arsenm wrote:

```suggestion
; ERR-I686: error: <unknown>:0:0: requesting 64-bit offset in 32-bit immediate: main
```



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