Wrong error about not capturing an already local variable

[JohelEGP]

The original code from #57958 still fails.
See https://godbolt.org/z/MbYYYKfv1.

#include <type_traits>

template<auto F> concept constant_invocable = requires { typename std::integral_constant<int, (F(), 0)>; };

template<class T>
constexpr bool C =
  [](auto) {
    return not constant_invocable<[]() {
      T v;
      (void)T{v};
    }>;
  }(0);

static_assert(C<int>);

<source>:10:15: warning: variable 'v' is uninitialized when used here [-Wuninitialized]
      (void)T{v};
              ^
<source>:14:15: note: in instantiation of variable template specialization 'C<int>' requested here
static_assert(C<int>);
              ^
<source>:9:10: note: initialize the variable 'v' to silence this warning
      T v;
         ^
          = 0
<source>:10:15: error: variable 'v' cannot be implicitly captured in a lambda with no capture-default specified
      (void)T{v};
              ^
<source>:7:3: note: in instantiation of function template specialization '(anonymous class)::operator()<int>' requested here
  [](auto) {
  ^
<source>:14:15: note: in instantiation of variable template specialization 'C<int>' requested here
static_assert(C<int>);
              ^
<source>:9:9: note: 'v' declared here
      T v;
        ^
<source>:8:35: note: lambda expression begins here
    return not constant_invocable<[]() {
                                  ^
<source>:8:36: note: capture 'v' by value
    return not constant_invocable<[]() {
                                   ^
                                   v
<source>:8:36: note: capture 'v' by reference
    return not constant_invocable<[]() {
                                   ^
                                   &v
<source>:8:36: note: default capture by value
    return not constant_invocable<[]() {
                                   ^
                                   =
<source>:8:36: note: default capture by reference
    return not constant_invocable<[]() {
                                   ^
                                   &
1 warning and 1 error generated.
Compiler returned: 1

[llvmbot]

@llvm/issue-subscribers-clang-frontend

[zyn0217]

Would be fixed by #107942.