[llvm] [ProfileData] Use std::vector for ValueData (NFC) (PR #95194)

[Mingming Liu via llvm-commits]

================
@@ -847,19 +847,26 @@ void InstrProfValueSiteRecord::merge(InstrProfValueSiteRecord &Input,
   Input.sortByTargetValues();
   auto I = ValueData.begin();
   auto IE = ValueData.end();
+  std::vector<InstrProfValueData> Merged;
+  Merged.reserve(std::max(ValueData.size(), Input.ValueData.size()));
   for (const InstrProfValueData &J : Input.ValueData) {
-    while (I != IE && I->Value < J.Value)
+    while (I != IE && I->Value < J.Value) {
+      Merged.push_back(*I);
       ++I;
+    }
     if (I != IE && I->Value == J.Value) {
       bool Overflowed;
       I->Count = SaturatingMultiplyAdd(J.Count, Weight, I->Count, &Overflowed);
       if (Overflowed)
         Warn(instrprof_error::counter_overflow);
+      Merged.push_back(*I);
       ++I;
       continue;
     }
-    ValueData.insert(I, J);
+    Merged.push_back(J);
   }
+  Merged.insert(Merged.end(), I, IE);
----------------
minglotus-6 wrote:

nit: I might slightly prefer something like

```
Iter1 = valueData.begin();
Iter2 = Input.ValueData.begin();
while(; Iter1 < valueData.end() && Iter2 < valueData.end();) {
  if (Iter1.Value > Iter2.Value)
    Merge.push_back(*Iter1);
  else if (Iter2.Value > Iter1.Value)
    Merge.push_back(*Iter2)
  else
    sum count and push
}
append the tail to Merged vector
```

https://github.com/llvm/llvm-project/pull/95194