Remove constexpr magic

Author: Advenam Tacet

libcxx/include/string

@@ -1891,9 +1891,8 @@ private:
 #if !defined(_LIBCPP_HAS_NO_ASAN) && defined(_LIBCPP_INSTRUMENTED_WITH_ASAN)
     const void* __begin = data();
     const void* __end   = data() + capacity() + 1;
-    if _LIBCPP_CONSTEXPR_SINCE_CXX17 (__asan_annotate_container_with_allocator<allocator_type>::value)
-      if(!__libcpp_is_constant_evaluated())
-        __sanitizer_annotate_contiguous_container(__begin, __end, __old_mid, __new_mid);
+    if (__asan_annotate_container_with_allocator<allocator_type>::value && !__libcpp_is_constant_evaluated())
+      __sanitizer_annotate_contiguous_container(__begin, __end, __old_mid, __new_mid);
 #endif
   }