move out of WTF namespace

Source/WTF/wtf/StdLibExtras.h

@@ -49,6 +49,20 @@
 
 WTF_ALLOW_UNSAFE_BUFFER_USAGE_BEGIN
 
+#if defined(__cpp_lib_bit_cast) && __cpp_lib_bit_cast >= 201806L
+#define __bit_cast std::bit_cast
+#else
+template <
+    typename Dest, typename Source,
+    typename std::enable_if<sizeof(Dest) == sizeof(Source) &&
+                                std::is_trivially_copyable<Source>::value &&
+                                std::is_trivially_copyable<Dest>::value,
+                            int>::type = 0>
+inline constexpr Dest __bit_cast(const Source &source) {
+  return __builtin_bit_cast(Dest, source);
+}
+#endif
+
 #define SINGLE_ARG(...) __VA_ARGS__ // useful when a macro argument includes a comma
 
 // Use this macro to declare and define a debug-only global variable that may have a
@@ -140,20 +154,6 @@ inline bool isPointerTypeAlignmentOkay(Type*)
 
 namespace WTF {
 
-#if defined(__cpp_lib_bit_cast) && __cpp_lib_bit_cast >= 201806L
-#define __bit_cast std::bit_cast
-#else
-template <
-    typename Dest, typename Source,
-    typename std::enable_if<sizeof(Dest) == sizeof(Source) &&
-                                std::is_trivially_copyable<Source>::value &&
-                                std::is_trivially_copyable<Dest>::value,
-                            int>::type = 0>
-inline constexpr Dest __bit_cast(const Source &source) {
-  return __builtin_bit_cast(Dest, source);
-}
-#endif
-
 enum CheckMoveParameterTag { CheckMoveParameter };
 
 static constexpr size_t KB = 1024;