[libc++] NFC: Remove unused macros in <__config>

libcxx/include/__config

@@ -442,10 +442,6 @@ typedef __char32_t char32_t;
 #  define _LIBCPP_NORETURN __attribute__ ((noreturn))
 #endif
 
-#if !(__has_feature(cxx_lambdas))
-#define _LIBCPP_HAS_NO_LAMBDAS
-#endif
-
 #if !(__has_feature(cxx_nullptr))
 #  if (__has_extension(cxx_nullptr) || __has_keyword(__nullptr)) && defined(_LIBCPP_ABI_ALWAYS_USE_CXX11_NULLPTR)
 #    define nullptr __nullptr
@@ -454,10 +450,6 @@ typedef __char32_t char32_t;
 #  endif
 #endif
 
-#if !(__has_feature(cxx_auto_type))
-#define _LIBCPP_HAS_NO_AUTO_TYPE
-#endif
-
 // Objective-C++ features (opt-in)
 #if __has_feature(objc_arc)
 #define _LIBCPP_HAS_OBJC_ARC