[llvm] [memprof] Add MemProf version (PR #86414)

[Teresa Johnson via llvm-commits]

================
@@ -528,7 +529,15 @@ Error InstrProfWriter::writeImpl(ProfOStream &OS) {
   // OnDiskChainedHashTable MemProfFrameData
   uint64_t MemProfSectionStart = 0;
   if (static_cast<bool>(ProfileKind & InstrProfKind::MemProf)) {
+    assert((MemProfVersionRequested == memprof::MemProfVersion0 ||
+            MemProfVersionRequested == memprof::MemProfVersion1) &&
+           "Requested MemProf version not supported");
+
     MemProfSectionStart = OS.tell();
+
+    if (MemProfVersionRequested == memprof::MemProfVersion1)
----------------
teresajohnson wrote:

Maybe generalize this so it doesn't have to be tweaked in future versions:

```
if (MemProfVersionRequested >= memprof::MemProfVersion1)
   OS.write(MemProfVersionRequested);
```

https://github.com/llvm/llvm-project/pull/86414