[clang] [LifetimeSafety] Warn when lifetimebound attribute is present on the definition but not on declaration (PR #197753)

[via cfe-commits]

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@@ -130,6 +130,16 @@ class LifetimeSafetySemaHelper {
   virtual void
   reportLifetimeboundViolation(const CXXMethodDecl *MDWithLifetimebound) {}
 
+  // Reports a member function definition that has [[clang::lifetimebound]] on
+  // the implicit this parameter when the previous declaration does not.
+  virtual void reportMisplacedLifetimebound(const FunctionDecl *FDef,
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NeKon69 wrote:

I mean, yeah, probably, but the reason I made this function accept `FunctionDecl` is that `getImplicitObjectParamLifetimeBoundAttr` later accepts a `FunctionDecl`, and we don't really use any `CXXMethodDecl` specific methods. So adding an explicit cast felt unnecessary to me. Do you think I should change that?

https://github.com/llvm/llvm-project/pull/197753