silence warnings under macOS for cc, clang and gcc

Used the following script to check for warnings
not silenced via ${CSILENCE}:

```sh
find ???? -mindepth 1 -maxdepth 1 -type d | while read dir; do
(cd "$dir"; echo =-=-= "$dir" =-=-= ; csilence -v 1 clobber all ; echo ; csilence -v 1 clobber alt)
done 2>&1 | less
```

2012/blakely/Makefile

@@ -38,7 +38,8 @@ include ../../var.mk
 
 # Common C compiler warnings to silence
 #
-CSILENCE= -Wno-error -Wno-implicit-function-declaration -Wno-unused-parameter
+CSILENCE= -Wno-error -Wno-implicit-function-declaration -Wno-unused-parameter \
+	-Wno-strict-prototypes
 
 # Common C compiler warning flags
 #

2012/deckmyn/Makefile

@@ -85,7 +85,8 @@ CC= cc
 ifeq ($(CC),clang)
 #
 CSILENCE+= -Wno-cast-align -Wno-comma -Wno-implicit-int-conversion \
-	-Wno-poison-system-directorie
+	-Wno-poison-system-directorie -Wno-unknown-warning-option \
+	-Wno-poison-system-directories
 #
 CWARN+= -Weverything
 #

2012/dlowe/Makefile

@@ -38,7 +38,7 @@ include ../../var.mk
 
 # Common C compiler warnings to silence
 #
-CSILENCE= -Wno-dangling-else
+CSILENCE= -Wno-dangling-else -Wno-strict-prototypes
 
 # Common C compiler warning flags
 #

2012/endoh1/Makefile

@@ -38,7 +38,7 @@ include ../../var.mk
 
 # Common C compiler warnings to silence
 #
-CSILENCE= -Wno-absolute-value
+CSILENCE= -Wno-absolute-value -Wno-strict-prototypes
 
 # Common C compiler warning flags
 #

2012/endoh2/Makefile

@@ -38,7 +38,7 @@ include ../../var.mk
 
 # Common C compiler warnings to silence
 #
-CSILENCE= -Wno-parentheses -Wno-empty-body
+CSILENCE= -Wno-parentheses -Wno-empty-body -Wno-strict-prototypes
 
 # Common C compiler warning flags
 #
@@ -84,7 +84,7 @@ CC= cc
 ifeq ($(CC),clang)
 #
 CSILENCE+= -Wno-comma -Wno-format-nonliteral -Wno-missing-variable-declarations \
-	-Wno-poison-system-directories
+	-Wno-poison-system-directories -Wno-float-conversion -Wno-implicit-int-conversion
 #
 CWARN+= -Weverything
 #

2012/hou/Makefile

@@ -41,7 +41,7 @@ include ../../var.mk
 CSILENCE= -Wno-error -Wno-implicit-function-declaration -Wno-format-extra-args \
 	-Wno-implicit-int -Wno-missing-field-initializers \
 	-Wno-non-literal-null-conversion -Wno-return-type -Wno-shift-op-parentheses \
-	-Wno-unused-parameter
+	-Wno-unused-parameter -Wno-deprecated-non-prototype
 
 # Common C compiler warning flags
 #

2012/kang/Makefile

@@ -39,7 +39,8 @@ include ../../var.mk
 # Common C compiler warnings to silence
 #
 CSILENCE= -Wno-bitwise-op-parentheses -Wno-error -Wno-implicit-function-declaration \
-	-Wno-implicit-int -Wno-int-conversion -Wno-pointer-to-int-cast
+	-Wno-implicit-int -Wno-int-conversion -Wno-pointer-to-int-cast \
+	-Wno-deprecated-non-prototype
 
 # Common C compiler warning flags
 #

2012/konno/Makefile

@@ -41,7 +41,7 @@ include ../../var.mk
 CSILENCE= -Wno-bitwise-conditional-parentheses -Wno-bitwise-op-parentheses \
 	-Wno-error -Wno-implicit-function-declaration -Wno-implicit-int \
 	-Wno-int-conversion -Wno-parentheses -Wno-pointer-to-int-cast \
-	-Wno-shift-op-parentheses
+	-Wno-shift-op-parentheses -Wno-deprecated-non-prototype
 
 # Common C compiler warning flags
 #

2012/omoikane/Makefile

@@ -38,7 +38,7 @@ include ../../var.mk
 
 # Common C compiler warnings to silence
 #
-CSILENCE= -Wno-empty-body
+CSILENCE= -Wno-empty-body -Wno-strict-prototypes
 
 # Common C compiler warning flags
 #

2012/tromp/Makefile

@@ -40,7 +40,8 @@ include ../../var.mk
 #
 CSILENCE= -Wno-bitwise-op-parentheses -Wno-conditional-type-mismatch -Wno-error \
 	-Wno-implicit-function-declaration -Wno-incompatible-pointer-types \
-	-Wno-int-conversion -Wno-main -Wno-return-type -Wno-unused-parameter
+	-Wno-int-conversion -Wno-main -Wno-return-type -Wno-unused-parameter \
+	-Wno-deprecated-non-prototype
 
 # Common C compiler warning flags
 #