Only check for GCC version if GCC is used. (#5)

This fixes #2.

Author: aentinger

src/storage/kv_storage/littlefs/kv_littlefs.cpp

@@ -11,7 +11,7 @@
 
 #include "kv_littlefs.h"
 
-#if __GNUC__ >= 11
+#if !defined(__GNUC__) || (__GNUC__ >= 11)
 
 #include <map>
 #include <string>
@@ -133,4 +133,4 @@ auto KeyValueStorage::drop(const std::string_view key) -> std::optional<Error>
 
 } /* cyphal::support::platform::storage::littlefs */
 
-#endif /* __GNUC__ >= 11 */
+#endif /* !defined(__GNUC__) || (__GNUC__ >= 11) */

src/storage/kv_storage/littlefs/kv_littlefs.h

@@ -14,7 +14,7 @@
 #include <107-Arduino-Cyphal.h>
 #include <107-Arduino-littlefs.h>
 
-#if __GNUC__ >= 11
+#if !defined(__GNUC__) || (__GNUC__ >= 11)
 
 /**************************************************************************************
  * NAMESPACE
@@ -55,4 +55,4 @@ class KeyValueStorage final : public interface::KeyValueStorage
 
 } /* cyphal::support::platform::storage::littlefs */
 
-#endif /* __GNUC__ >= 11 */
+#endif /* !defined(__GNUC__) || (__GNUC__ >= 11) */