[clang] [clang] Infer lifetime_capture_by for STL containers (PR #117122)

[Utkarsh Saxena via cfe-commits]

================
@@ -268,6 +268,40 @@ void Sema::inferLifetimeBoundAttribute(FunctionDecl *FD) {
   }
 }
 
+static bool IsPointerLikeType(QualType QT) {
+  QT = QT.getNonReferenceType();
+  if (QT->isPointerType())
+    return true;
+  auto *RD = QT->getAsCXXRecordDecl();
+  if (!RD)
+    return false;
+  RD = RD->getCanonicalDecl();
+  if (auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(RD))
+    RD = CTSD->getSpecializedTemplate()->getTemplatedDecl();
----------------
usx95 wrote:

> Should we do the same thing for the one in CheckExprLifetime.cpp?
Makes a lot of sense. Let me do this separately in parallel though.

That said, your example still doesn't work show the warning with the lines removed:
```cpp
   if (auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(RD))
     RD = CTSD->getSpecializedTemplate()->getTemplatedDecl();
```

https://github.com/llvm/llvm-project/pull/117122