libstdc++: Reduce uses of std::numeric_limits

This avoids unnecessary instantiations of std::numeric_limits or
inclusion of <limits> when a more lightweight alternative would work.
Some uses can be replaced with __gnu_cxx::__int_traits and some can just
use size_t(-1) directly where SIZE_MAX is needed.

libstdc++-v3/ChangeLog:

	* include/bits/regex.h: Use __int_traits<int> instead of
	std::numeric_limits<int>.
	* include/bits/uniform_int_dist.h: Use __int_traits<T>::__max
	instead of std::numeric_limits<T>::max().
	* include/bits/hashtable_policy.h: Use size_t(-1) instead of
	std::numeric_limits<size_t>::max().
	* include/std/regex: Include <ext/numeric_traits.h>.
	* include/std/string_view: Use typedef for __int_traits<int>.
	* src/c++11/hashtable_c++0x.cc: Use size_t(-1) instead of
	std::numeric_limits<size_t>::max().
	* testsuite/std/ranges/iota/96042.cc: Include <limits>.
	* testsuite/std/ranges/iota/difference_type.cc: Likewise.
	* testsuite/std/ranges/subrange/96042.cc: Likewise.

1 files changed, 5 insertions, 4 deletions

diff --git a/libstdc++-v3/include/bits/regex.h b/libstdc++-v3/include/bits/regex.h
index 31ebcc1eb86..15e4289bf95 100644
--- a/libstdc++-v3/include/bits/regex.h
+++ b/libstdc++-v3/include/bits/regex.h
@@ -973,11 +973,12 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 	  if (const size_t __n = std::min(_M_len, __s._M_len))
 	    if (int __ret = traits_type::compare(_M_data, __s._M_data, __n))
 	      return __ret;
+	  using __limits = __gnu_cxx::__int_traits<int>;
 	  const difference_type __diff = _M_len - __s._M_len;
-	  if (__diff > std::numeric_limits<int>::max())
-	    return std::numeric_limits<int>::max();
-	  if (__diff < std::numeric_limits<int>::min())
-	    return std::numeric_limits<int>::min();
+	  if (__diff > __limits::__max)
+	    return __limits::__max;
+	  if (__diff < __limits::__min)
+	    return __limits::__min;
 	  return static_cast<int>(__diff);
 	}