silence compiler warnings for RHEL 9 Linux

We updated ${CSILENCE} Makefile variables for entries in an attempt to
minimize compiler warnings.  This was tested using
gcc version 11.4.1 20230605 (Red Hat 11.4.1-2) (GCC).

TODO: Recheck macOS clang to see if any new warnings have occur
      under macOS clang.

2004/vik1/Makefile

@@ -38,7 +38,8 @@ include ../../var.mk
 
 # Common C compiler warnings to silence
 #
-CSILENCE= -Wno-bitwise-conditional-parentheses -Wno-format-extra-args
+CSILENCE= -Wno-bitwise-conditional-parentheses -Wno-format-extra-args \
+	  -Wno-int-in-bool-context -Wno-parentheses
 
 # Common C compiler warning flags
 #
@@ -84,8 +85,8 @@ CC= cc
 ifeq "$(findstring $(CLANG),${CC})" "$(CLANG)"
 #
 CSILENCE+= -Wno-cast-align -Wno-comma -Wno-float-conversion \
-	-Wno-missing-variable-declarations -Wno-poison-system-directories \
-	-Wno-sign-conversion
+	   -Wno-missing-variable-declarations -Wno-poison-system-directories \
+	   -Wno-sign-conversion -Wno-unsafe-buffer-usage
 #
 CWARN+= -Weverything
 #