[llvm] [DRAFT] coros: suspend metadata preservation (PR #150077)

[Christian Ulmann via llvm-commits]

================
@@ -79,6 +79,20 @@ using namespace llvm;
 
 #define DEBUG_TYPE "coro-split"
 
+/// If set, ensures that all metadata from CoroSuspendInst's is preserved in the
+/// containing function.
+namespace llvm {
+static cl::opt<bool> CoroSplitPreservesSuspendMD(
+  "coro-split-preserves-suspend-md", cl::Hidden,
+  cl::desc("llvm.coro.suspend_md metadata from all suspend point instructions "
+          "will be preserved inside llvm.coro.suspend_md_table metadata on the "
+          "containing coroutine"));
+
+static StringRef CoroSuspendMDName = "llvm.coro.suspend_md";
+static StringRef CoroSuspendMDTableName = "llvm.coro.suspend_md_table";
----------------
Dinistro wrote:

```suggestion
static constexpr StringRef CoroSuspendMDName = "llvm.coro.suspend_md";
static constexpr StringRef CoroSuspendMDTableName = "llvm.coro.suspend_md_table";
```

https://github.com/llvm/llvm-project/pull/150077