[libc++] Turn off clang-format for auto-generated version header. NFC.

Author: mkurdej

libcxx/include/version

@@ -170,6 +170,8 @@ __cpp_lib_void_t                                        201411L <type_traits>
 #pragma GCC system_header
 #endif
 
+// clang-format off
+
 #if _LIBCPP_STD_VER > 11
 # define __cpp_lib_chrono_udls                          201304L
 # define __cpp_lib_complex_udls                         201309L
@@ -365,4 +367,6 @@ __cpp_lib_void_t                                        201411L <type_traits>
 # define __cpp_lib_string_contains                      202011L
 #endif
 
+// clang-format on
+
 #endif // _LIBCPP_VERSIONH

libcxx/utils/generate_feature_test_macro_components.py

@@ -820,8 +820,12 @@ def produce_version_header():
 #pragma GCC system_header
 #endif
 
+// clang-format off
+
 {cxx_macros}
 
+// clang-format on
+
 #endif // _LIBCPP_VERSIONH
 """