*: mass renaming of USE_XXXX to IF_XXXX
and SKIP_XXXX to IF_NOT_XXXX - the second one was especially
badly named. It was not skipping anything!

diff --git a/findutils/xargs.c b/findutils/xargs.c
index f22d089..76d1d54 100644
--- a/findutils/xargs.c
+++ b/findutils/xargs.c
@@ -356,9 +356,9 @@
 	OPTBIT_UPTO_SIZE,
 	OPTBIT_EOF_STRING,
 	OPTBIT_EOF_STRING1,
-	USE_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
-	USE_FEATURE_XARGS_SUPPORT_TERMOPT(     OPTBIT_TERMINATE  ,)
-	USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(   OPTBIT_ZEROTERM   ,)
+	IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
+	IF_FEATURE_XARGS_SUPPORT_TERMOPT(     OPTBIT_TERMINATE  ,)
+	IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(   OPTBIT_ZEROTERM   ,)
 
 	OPT_VERBOSE     = 1 << OPTBIT_VERBOSE    ,
 	OPT_NO_EMPTY    = 1 << OPTBIT_NO_EMPTY   ,
@@ -366,14 +366,14 @@
 	OPT_UPTO_SIZE   = 1 << OPTBIT_UPTO_SIZE  ,
 	OPT_EOF_STRING  = 1 << OPTBIT_EOF_STRING , /* GNU: -e[<param>] */
 	OPT_EOF_STRING1 = 1 << OPTBIT_EOF_STRING1, /* SUS: -E<param> */
-	OPT_INTERACTIVE = USE_FEATURE_XARGS_SUPPORT_CONFIRMATION((1 << OPTBIT_INTERACTIVE)) + 0,
-	OPT_TERMINATE   = USE_FEATURE_XARGS_SUPPORT_TERMOPT(     (1 << OPTBIT_TERMINATE  )) + 0,
-	OPT_ZEROTERM    = USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(   (1 << OPTBIT_ZEROTERM   )) + 0,
+	OPT_INTERACTIVE = IF_FEATURE_XARGS_SUPPORT_CONFIRMATION((1 << OPTBIT_INTERACTIVE)) + 0,
+	OPT_TERMINATE   = IF_FEATURE_XARGS_SUPPORT_TERMOPT(     (1 << OPTBIT_TERMINATE  )) + 0,
+	OPT_ZEROTERM    = IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(   (1 << OPTBIT_ZEROTERM   )) + 0,
 };
 #define OPTION_STR "+trn:s:e::E:" \
-	USE_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \
-	USE_FEATURE_XARGS_SUPPORT_TERMOPT(     "x") \
-	USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(   "0")
+	IF_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \
+	IF_FEATURE_XARGS_SUPPORT_TERMOPT(     "x") \
+	IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(   "0")
 
 int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int xargs_main(int argc, char **argv)
@@ -405,7 +405,7 @@
 		eof_str = NULL;
 
 	if (opt & OPT_ZEROTERM)
-		USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
+		IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
 
 	argv += optind;
 	argc -= optind;