[Clang][regression] Clang crashes when type of function parameter pack of inner lambda is decltype(outer_lambda_function_parameter_pack) and inner lambda has requires clause

[zwuis]

This code makes Clang 16 and newer versions crash:

void test() {
  auto L = [](auto... x) {
    return [](decltype(x)... y) requires true {};
  };
  L(0, 1)(1, 2);
}

Compiler Explorer: https://godbolt.org/z/831x11eEr

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Yanzuo Liu (zwuis)

This code makes Clang 16 and newer versions crash:

void test() {
  auto L = [](auto... x) {
    return [](decltype(x)... y) requires true {};
  };
  L(0, 1)(1, 2);
}

Compiler Explorer: <https://godbolt.org/z/831x11eEr>

[zyn0217]

SetupConstraintScope is not handling nested lambdas very well. I think we might want to delegate the job to LambdaScopeForCallOperatorInstantiationRAII which handles both captures and parameters dedicatedly.