[llvm] [AggressiveInstCombine] Inline strcmp/strncmp (PR #89371)

[Franklin Zhang via llvm-commits]

FLZ101 wrote:

> It looks like this patch crashes when compiling lencod from llvm-test-suite in ReleaseLTO-g configuration: https://llvm-compile-time-tracker.com/show_error.php?commit=73bf9d626bf3fb7a43453f6731f1aecab83177b4

It seems to be a bug related to the new DebugInfo, I found the change as below could fix it.

```diff
--- a/llvm/lib/IR/BasicBlock.cpp
+++ b/llvm/lib/IR/BasicBlock.cpp
@@ -1009,7 +1009,7 @@ void BasicBlock::spliceDebugInfoImpl(BasicBlock::iterator Dest, BasicBlock *Src,
     // generate the iterator with begin() / getFirstInsertionPt(), it means
     // any trailing debug-info at the end of the block would "normally" have
     // been pushed in front of "First". Move it there now.
-    DbgMarker *FirstMarker = getMarker(First);
+    DbgMarker *FirstMarker = createMarker(First);
     DbgMarker *TrailingDbgRecords = getTrailingDbgRecords();
     if (TrailingDbgRecords) {
       FirstMarker->absorbDebugValues(*TrailingDbgRecords, true);
```

I am preparing a minimal test case and will create a new pull request to fix this bug soon.

https://github.com/llvm/llvm-project/pull/89371