Add non-public API for internal users

PiperOrigin-RevId: 532553508
Change-Id: I813841ff3e5085b64c9b02ca41897bf7f6a8570e
diff --git a/absl/status/status.h b/absl/status/status.h
index c6c1cd4..595064c 100644
--- a/absl/status/status.h
+++ b/absl/status/status.h
@@ -886,6 +886,15 @@
 // message-less kCancelled errors are common in the infrastructure.
 inline Status CancelledError() { return Status(absl::StatusCode::kCancelled); }
 
+// Retrieves a message's status as a null terminated C string. The lifetime of
+// this string is tied to the lifetime of the status object itself.
+//
+// If the status's message is empty, the empty string is returned.
+//
+// StatusMessageAsCStr exists for C support. Use `status.message()` in C++.
+const char* StatusMessageAsCStr(
+    const Status& status ABSL_ATTRIBUTE_LIFETIME_BOUND);
+
 ABSL_NAMESPACE_END
 }  // namespace absl