[llvm] [PDB] Fix and simplify module index lookup (PR #179869)

[via llvm-commits]

================
@@ -410,20 +410,16 @@ uint64_t NativeSession::getVAFromSectOffset(uint32_t Section,
 bool NativeSession::moduleIndexForVA(uint64_t VA, uint16_t &ModuleIndex) const {
   ModuleIndex = 0;
   auto Iter = AddrToModuleIndex.find(VA);
-  if (Iter == AddrToModuleIndex.end())
-    return false;
-  ModuleIndex = Iter.value();
-  return true;
+  if (Iter.valid() && !IMap::KeyTraits::startLess(VA, Iter.start())) {
----------------
Nerixyz wrote:

```suggestion
  if (Iter.valid() && VA >= Iter.start()) {
```

This is easier to read, in my opinion.

https://github.com/llvm/llvm-project/pull/179869