limits: Use `false` instead of `type(0)`.

[brucem]

Summary

This fixes warnings when using clang-tidy and the
modernize-use-bool-literals check.

[mclow.lists]

I see no benefit to this change. bool(0) is false.

[brucem]

Without this, anyone using clang-tidy with this check gets 6 system header warnings whenever they transitively have included limits.

[lebedev.ri]

In D43277#1009659, @brucem wrote:

Without this, anyone using clang-tidy with this check gets 6 system header warnings whenever they transitively have included limits.

Only if -system-headers is passed to clang-tidy, or if those libc++ headers are included as normal includes (-I), and not as system includes (-isystem).

include/limits

protected:
     static _LIBCPP_CONSTEXPR const type __max = true;
     _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __min;}
     _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __max;}
     _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return min();}
 
     static _LIBCPP_CONSTEXPR const bool is_integer = true;
     static _LIBCPP_CONSTEXPR const bool is_exact = true;
     static _LIBCPP_CONSTEXPR const int  radix = 2;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return type(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return type(0);}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return false;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return false;}
 
     static _LIBCPP_CONSTEXPR const int  min_exponent = 0;
     static _LIBCPP_CONSTEXPR const int  min_exponent10 = 0;
     static _LIBCPP_CONSTEXPR const int  max_exponent = 0;
     static _LIBCPP_CONSTEXPR const int  max_exponent10 = 0;
 
     static _LIBCPP_CONSTEXPR const bool has_infinity = false;
     static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = false;
     static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = false;
     static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_absent;
     static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return type(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return type(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return type(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return type(0);}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return false;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return false;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return false;}
+    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return false;}
 
     static _LIBCPP_CONSTEXPR const bool is_iec559 = false;
     static _LIBCPP_CONSTEXPR const bool is_bounded = true;
     static _LIBCPP_CONSTEXPR const bool is_modulo = false;
 
     static _LIBCPP_CONSTEXPR const bool traps = false;
     static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
     static _LIBCPP_CONSTEXPR const float_round_style round_style = round_toward_zero;