PathFuncs: correct helper comment

Summary:
# This diff
fixes a comment to be more clear about the current language limitations

# context

I spent some time refactoring the code to remove this helper since I thought C++20 would remove the need for it. However, I soon discovered that the constructor added in C++20 is not noexcept, so we cannot utilize it directly. Therefore, we must continue to use this helper. Clarify the comment to avoid other people wasting their time in the future :)

Reviewed By: jdelliot

Differential Revision: D66115291

fbshipit-source-id: 634fcf4ddbe8749b4c52f5f24dc14ef663946d8c

eden/common/utils/PathFuncs.h

@@ -131,7 +131,9 @@ T move_or_copy(T& t) noexcept {
 }
 
 /**
- * C++20 introduces this constructor for std::string_view, but EdenFS is C++17.
+ * C++20 introduces this constructor for std::string_view. However, this doesn't
+ * matter for our use case, since the new constructor is not NOEXCEPT and
+ * therefore cannot be utilized in many places.
  */
 inline std::string_view string_view_range(const char* begin, const char* end) {
   XDCHECK_LE(begin, end);