Ignore only warnings known by clang

Clang 17 does not know warning group '-Wgnu-empty-initializer'.

Author: nobu

addr2line.c

@@ -8,10 +8,14 @@
 
 **********************************************************************/
 
-#if defined(__clang__)
+#if defined(__clang__) && defined(__has_warning)
+#if __has_warning("-Wgnu-empty-initializer")
 #pragma clang diagnostic ignored "-Wgnu-empty-initializer"
+#endif
+#if __has_warning("-Wgcc-compat")
 #pragma clang diagnostic ignored "-Wgcc-compat"
 #endif
+#endif
 
 #include "ruby/internal/config.h"
 #include "ruby/defines.h"