add CUNKNOWN make variables to entry Makefiles

1993/plummer/Makefile

@@ -41,11 +41,15 @@ include ../../var.mk
 CSILENCE= -Wno-error -Wno-implicit-function-declaration -Wno-format-security \
 	  -Wno-deprecated-non-prototype -Wno-implicit-int \
 	  -Wno-builtin-declaration-mismatch -Wno-missing-parameter-type \
-          -Wno-return-type -Wno-unknown-warning-option
+          -Wno-return-type
+
+# Attempt to silence unknown warnings
+#
+CUNKNOWN= -Wno-unknown-warning-option
 
 # Common C compiler warning flags
 #
-CWARN= -Wall -Wextra ${CSILENCE}
+CWARN= -Wall -Wextra ${CSILENCE} ${CUNKNOWN}
 
 # Compiler standard
 #
@@ -53,9 +57,6 @@ CSTD= -std=gnu90
 
 # Compiler bit architecture
 #
-# Some entries require 32-bitness: ARCH= -m32
-# Some entries require 64-bitness: ARCH= -m64
-#
 ARCH=
 
 # Defines that are needed to compile
@@ -87,8 +88,7 @@ CC= cc
 ifeq "$(findstring $(CLANG),${CC})" "$(CLANG)"
 #
 CSILENCE+= -Wno-comma -Wno-implicit-int-conversion -Wno-missing-variable-declarations \
-	   -Wno-pedantic -Wno-poison-system-directories -Wno-unknown-warning-option \
-	   -Wno-unsafe-buffer-usage
+	   -Wno-pedantic -Wno-poison-system-directories -Wno-unsafe-buffer-usage
 #
 CWARN+= -Weverything
 #