[clang] [LifetimeSafety] Warn on incorrectly placed `[[clang::lifetimebound]]` attributes (PR #196144)

[Gábor Horváth via cfe-commits]

================
@@ -358,6 +362,18 @@ class LifetimeChecker {
     }
   }
 
+  void reportLifetimeboundViolations() {
+    if (!isa<FunctionDecl>(FD))
+      return;
+    for (const ParmVarDecl *PVD : cast<FunctionDecl>(FD)->parameters()) {
+      if (!PVD->hasAttr<LifetimeBoundAttr>())
+        continue;
+      if (!PVD->getAttr<LifetimeBoundAttr>()->isImplicit() &&
----------------
Xazax-hun wrote:

Yeah, I was thinking of an assert fail. That being said if we cannot come up with a sensible assert that would not be triggered currently, I am also fine leaving this as is. 

https://github.com/llvm/llvm-project/pull/196144