[llvm] [InstCombine] Fold `getelementptr inbounds null, idx -> null` (PR #130742)

[Matt Arsenault via llvm-commits]

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@@ -3,7 +3,7 @@
 
 %"struct.__llvm_libc::rpc::Buffer" = type { [8 x i64] }
 
-define void @issue63986(i64 %0, i64 %idxprom) {
+define void @issue63986(i64 %0, i64 %idxprom) null_pointer_is_valid {
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arsenm wrote:

```suggestion
define void @issue63986(i64 %0, i64 %idxprom, ptr inreg %ptr) {
```


https://github.com/llvm/llvm-project/pull/130742