Update Ruby warning suppressions for Clang

Author: rra

Makefile.am

@@ -366,7 +366,9 @@ RUBY_WARNINGS = -Wno-strict-prototypes -Wno-redundant-decls -Wno-conversion \
 	-Wno-gcc-compat -Wno-extra-semi-stmt -Wno-strict-overflow -Wno-vla  \
 	-Wno-gnu-zero-variadic-macro-arguments				    \
 	-Wno-declaration-after-statement -Wno-unknown-attributes	    \
-	-Wno-ignored-attributes
+	-Wno-ignored-attributes -Wno-c23-extensions			    \
+	-Wno-documentation-unknown-command -Wno-unused-parameter	    \
+	-Wno-documentation-deprecated-sync
 
 warnings:
 	$(MAKE) V=0					\