[llvm] [StaticDataLayout][PGO]Implement reader and writer change for data access profiles (PR #139997)

[Mingming Liu via llvm-commits]

================
@@ -10,14 +10,20 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/ProfileData/DataAccessProf.h"
 #include "llvm/ProfileData/InstrProf.h"
 #include "llvm/ProfileData/MemProf.h"
 
+#include <functional>
+#include <optional>
+
 namespace llvm {
 
 // Write the MemProf data to OS.
-Error writeMemProf(ProfOStream &OS, memprof::IndexedMemProfData &MemProfData,
-                   memprof::IndexedVersion MemProfVersionRequested,
-                   bool MemProfFullSchema);
+Error writeMemProf(
+    ProfOStream &OS, memprof::IndexedMemProfData &MemProfData,
+    memprof::IndexedVersion MemProfVersionRequested, bool MemProfFullSchema,
+    std::optional<std::reference_wrapper<data_access_prof::DataAccessProfData>>
----------------
mingmingl-llvm wrote:

> I think there is no need for the DataAccessProf record object to be valid after `writeMemProf` is called. How about just use `std::unique_ptr<DataAccessProfData>` as the param and move the contents here if valid. Then we can check if the pointer is not null inside. Wdyt?

Sounds reasonable. Done.

> If you change the namespace to memprof then you won't need this extra qualification here.

To save `memprof::` before `writeMemProf` parameters, we need to put `writeMemProf` function inside `memprof` namespace. I don't feel strong about this, and removing `optional<reference_wrapper<T>>` already simplified parameter a lot.

https://github.com/llvm/llvm-project/pull/139997