[Clang] Fix lambda CheckForDefaultedFunction(...) so that it checks the CXXMethodDecl is not deleted before attempting to call DefineDefaultedFunction(...)

I discovered this additional bug at the end of working on D132906

In Sema::CheckCompletedCXXClass(...)  uses a lambda CheckForDefaultedFunction to
verify each CXXMethodDecl holds to the expected invariants before passing them
on to CheckForDefaultedFunction.

It is currently missing a check that it is not deleted, this adds that check and
a test that crashed without this check.

This fixes: https://github.com/llvm/llvm-project/issues/57516

Differential Revision: https://reviews.llvm.org/D133177

clang/docs/ReleaseNotes.rst

@@ -89,6 +89,8 @@ Bug Fixes
 - Fix a crash when attempting to default a virtual constexpr non-special member
   function in a derived class. This fixes
   `Issue 57431 <https://github.com/llvm/llvm-project/issues/57431>`_
+- Fix a crash where we attempt to define a deleted destructor. This fixes
+  `Issue 57516 <https://github.com/llvm/llvm-project/issues/57516>`_
 
 
 Improvements to Clang's diagnostics

clang/lib/Sema/SemaDeclCXX.cpp

@@ -6954,8 +6954,8 @@ void Sema::CheckCompletedCXXClass(Scope *S, CXXRecordDecl *Record) {
     // Define defaulted constexpr virtual functions that override a base class
     // function right away.
     // FIXME: We can defer doing this until the vtable is marked as used.
-    if (CSM != CXXInvalid && M->isDefaulted() && M->isConstexpr() &&
-        M->size_overridden_methods())
+    if (CSM != CXXInvalid && !M->isDeleted() && M->isDefaulted() &&
+        M->isConstexpr() && M->size_overridden_methods())
       DefineDefaultedFunction(*this, M, M->getLocation());
 
     if (!Incomplete)

clang/test/SemaCXX/constant-expression-cxx2a.cpp

@@ -1483,3 +1483,12 @@ class D : B {
   virtual int constexpr f() = default; // expected-error {{only special member functions and comparison operators may be defaulted}}
 };
 }
+
+namespace GH57516 {
+class B{
+  virtual constexpr ~B() = 0; // expected-note {{overridden virtual function is here}}
+};
+
+class D : B{}; // expected-error {{deleted function '~D' cannot override a non-deleted function}}
+// expected-note@-1 {{destructor of 'D' is implicitly deleted because base class 'B' has an inaccessible destructor}}
+}