Fix think-o and add test coverage to ensure it doesn't happen again

Author: AaronBallman

clang/lib/Sema/SemaExceptionSpec.cpp

@@ -1206,8 +1206,8 @@ CanThrowResult Sema::canThrow(const Stmt *S) {
       CT = CT_Dependent;
     } else {
       const FunctionDecl *OperatorDelete = DE->getOperatorDelete();
+      CT = canCalleeThrow(*this, DE, OperatorDelete);
       if (!OperatorDelete->isDestroyingOperatorDelete()) {
-        CT = canCalleeThrow(*this, DE, OperatorDelete);
         if (const RecordType *RT = DTy->getAs<RecordType>()) {
           const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
           const CXXDestructorDecl *DD = RD->getDestructor();

clang/test/SemaCXX/noexcept-destroying-delete.cpp

@@ -19,3 +19,15 @@ struct Explicit {
 Explicit *qn = nullptr;
 // This assertion used to fail, see GH118660
 static_assert(noexcept(delete(qn)));
+
+struct ThrowingDestroyingDelete {
+    ~ThrowingDestroyingDelete() noexcept(false) {}
+
+    void operator delete(ThrowingDestroyingDelete*, std::destroying_delete_t) noexcept(false) {
+    }
+};
+
+ThrowingDestroyingDelete *pn = nullptr;
+// noexcept should return false here because the destroying delete itself is a
+// potentially throwing function.
+static_assert(!noexcept(delete(pn)));