[llvm] [EarlyCSE] Fix dead store elimination for unwinding readnone calls (PR #145287)

[Yingwei Zheng via llvm-commits]

================
@@ -1525,6 +1525,11 @@ bool EarlyCSE::processNode(DomTreeNode *Node) {
       }
     }
 
+    // Make sure stores prior to a potential unwind are not removed, as the
+    // caller may read the memory.
+    if (Inst.mayThrow())
----------------
dtcxzyw wrote:

All the target memory store intrinsics have `nounwind`, right?


https://github.com/llvm/llvm-project/pull/145287