Sema: Fixes a crash with a templated destructor

[Mordante]

Summary

This fixes PR38671.
The issue was introduced by D33833 which fixed PR33189.

[aaron.ballman]

LGTM

clang/lib/Sema/SemaLookup.cpp

Sema::SpecialMemberOverloadResult Sema::LookupSpecialMember(CXXRecordDecl *RD,
 
   if (SM == CXXDestructor) {
     if (RD->needsImplicitDestructor()) {
       runWithSufficientStackSpace(RD->getLocation(), [&] {
         DeclareImplicitDestructor(RD);
       });
     }
     CXXDestructorDecl *DD = RD->getDestructor();
-    assert(DD && "record without a destructor");
     Result->setMethod(DD);
-    Result->setKind(DD->isDeleted() ?
-                    SpecialMemberOverloadResult::NoMemberOrDeleted :
-                    SpecialMemberOverloadResult::Success);
+    Result->setKind(DD && !DD->isDeleted()
+                        ? SpecialMemberOverloadResult::Success
+                        : SpecialMemberOverloadResult::NoMemberOrDeleted);
     return *Result;
   }
 
   // Prepare for overload resolution. Here we construct a synthetic argument
   // if necessary and make sure that implicit functions are declared.
   CanQualType CanTy = Context.getCanonicalType(Context.getTagDeclType(RD));
   DeclarationName Name;
   Expr *Arg = nullptr;

clang/test/SemaTemplate/destructor-template.cpp

namespace PR16852 {
   void g() { f(); } // expected-error {{no matching function for call to 'f'}}
 }
 
 class PR33189
 {
   template <class T>
   ~PR33189() { } // expected-error{{destructor cannot be declared as a template}}
 };
+
+namespace PR38671 {
+struct S {
+  template <class>
+  ~S(); // expected-error{{destructor cannot be declared as a template}}
+};
+struct T : S {    // expected-note{{destructor of 'T' is implicitly deleted because base class 'PR38671::S' has no destructor}}
+  ~T() = default; // expected-warning{{explicitly defaulted destructor is implicitly deleted}}
+};
+} // namespace PR38671