silence most warnings under macOS

For macOS Apple clang version 15.0.0 (clang-1500.3.9.4)
compiler, we have silenced the warnings that can be silenced.

We also updated `.gitignore` for `2014/maffiodo2` and `1995/vanschnitz`.

1987/biggar/Makefile

@@ -39,7 +39,7 @@ include ../../var.mk
 # Common C compiler warnings to silence
 #
 CSILENCE= -Wno-error -Wno-implicit-function-declaration -Wno-extra-semi \
-	-Wno-strict-prototypes
+	-Wno-strict-prototypes -Wno-implicit-int
 
 # Common C compiler warning flags
 #

1987/heckbert/Makefile

@@ -85,7 +85,8 @@ CC= cc
 ifeq "$(findstring $(CLANG),${CC})" "$(CLANG)"
 #
 CSILENCE+= -Wno-comma -Wno-missing-prototypes -Wno-missing-variable-declarations \
-	-Wno-pedantic -Wno-poison-system-directories -Wno-shadow -Wno-strict-prototypes
+	-Wno-pedantic -Wno-poison-system-directories -Wno-shadow -Wno-strict-prototypes \
+	-Wno-unused-macros
 #
 CWARN+= -Weverything
 #

1987/lievaart/Makefile

@@ -86,7 +86,8 @@ ifeq "$(findstring $(CLANG),${CC})" "$(CLANG)"
 #
 CSILENCE+= -Wno-comma -Wno-conditional-uninitialized -Wno-missing-prototypes \
 	-Wno-missing-variable-declarations -Wno-pedantic \
-	-Wno-poison-system-directories -Wno-shadow -Wno-strict-prototypes
+	-Wno-poison-system-directories -Wno-shadow -Wno-strict-prototypes \
+	-Wno-unused-macros
 #
 CWARN+= -Weverything
 #