Try another workaround for __has_builtin-related breakages (https://github.com/pybind/pybind11/runs/7430720321).

Author: rwgk

include/pybind11/detail/descr.h

@@ -42,11 +42,12 @@ PYBIND11_NAMESPACE_BEGIN(detail)
 //   (line numbers vary between translation units).
 #if defined(PYBIND11_ENABLE_TYPE_CASTER_ODR_GUARD_IF_AVAILABLE)                                   \
     && !defined(PYBIND11_ENABLE_TYPE_CASTER_ODR_GUARD) && defined(PYBIND11_CPP17)                 \
-    && !defined(__INTEL_COMPILER)                                                                 \
-    && ((defined(_MSC_VER) && _MSC_VER >= 1920)                                                   \
-        || (defined(__has_builtin) && __has_builtin(__builtin_FILE)                               \
-            && __has_builtin(__builtin_LINE)))
-#    define PYBIND11_ENABLE_TYPE_CASTER_ODR_GUARD
+    && !defined(__INTEL_COMPILER) && (!defined(_MSC_VER) || _MSC_VER >= 1920)                     \
+    && defined(__has_builtin)
+// This needs to be a nested #if to not upset older compilers.
+#    if __has_builtin(__builtin_FILE) && __has_builtin(__builtin_LINE)
+#        define PYBIND11_ENABLE_TYPE_CASTER_ODR_GUARD
+#    endif
 #endif
 
 #ifdef PYBIND11_ENABLE_TYPE_CASTER_ODR_GUARD