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.

1986/wall/Makefile

@@ -39,9 +39,11 @@ include ../../var.mk
 # Common C compiler warnings to silence
 #
 CSILENCE= -Wno-error -Wno-implicit-function-declaration -Wno-implicit-int \
-	-Wno-parentheses -Wno-c99-extensions -Wno-declaration-after-statement \
-	-Wno-deprecated-non-prototype -Wno-strict-prototypes -Wno-string-plus-char \
-	-Wno-macro-redefined
+	  -Wno-parentheses -Wno-c99-extensions -Wno-declaration-after-statement \
+	  -Wno-deprecated-non-prototype -Wno-strict-prototypes \
+	  -Wno-string-plus-char -Wno-macro-redefined \
+	  -Wno-builtin-declaration-mismatch -Wno-pedantic \
+	  -Wno-implicit-fallthrough -Wno-return-type
 
 # Common C compiler warning flags
 #
@@ -87,9 +89,10 @@ CC= cc
 ifeq "$(findstring $(CLANG),${CC})" "$(CLANG)"
 #
 CSILENCE+= -Wno-implicit-int-conversion -Wno-missing-prototypess \
-	-Wno-missing-variable-declarations -Wno-poison-system-directories \
-	-Wno-strict-prototypes -Wno-missing-prototypes -Wno-unknown-warning-option \
-	-Wno-unused-macros
+	   -Wno-missing-variable-declarations -Wno-poison-system-directories \
+	   -Wno-strict-prototypes -Wno-missing-prototypes -Wno-unknown-warning-option \
+	   -Wno-unused-macros -Wno-extra-semi-stmt -Wno-reserved-macro-identifier \
+	   -Wno-unsafe-buffer-usage
 #
 CWARN+= -Weverything
 #