fix is_reflection_type

[Tsche]

is_reflection_type currently compares a reflection against the type alias std::meta::info instead of the aliased reflection type. We need to dealias it to check against the aliased type instead of the alias itself.

Consider the following example:

static_assert(is_reflection_type(^^std::meta::info)); // passes, we are comparing aliases
static_assert(not is_reflection_type(type_of(reflect_constant(^^int)))); // oops
static_assert(not is_reflection_type(^^decltype(^^int))); // oops

Dealiasing both the reflection r and std::meta::info makes all these assertions pass as expected:

consteval auto is_reflection_type(info r) -> bool {
  return dealias(r) == dealias(^^info);
}

// correct behavior: 
static_assert(is_reflection_type(^^std::meta::info));
static_assert(is_reflection_type(type_of(reflect_constant(^^int))));
static_assert(is_reflection_type(^^decltype(^^int)));

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