main: include +/-wcwidth in version output

* +wcwidth: use our own, builtin, wcwidth()
* -wcwidth: use system’s wcwidth()

foot-features.h

@@ -37,3 +37,12 @@ static inline bool feature_graphemes(void)
     return false;
 #endif
 }
+
+static inline bool feature_builtin_wcwidth(void)
+{
+#if FOOT_SYSTEM_WCWIDTH == 0
+    return true;
+#else
+    return false;
+#endif
+}

main.c

@@ -45,12 +45,13 @@ static const char *
 version_and_features(void)
 {
     static char buf[256];
-    snprintf(buf, sizeof(buf), "version: %s %cpgo %cime %cgraphemes %cassertions",
+    snprintf(buf, sizeof(buf), "version: %s %cpgo %cime %cgraphemes %cassertions %cwcwidth",
              FOOT_VERSION,
              feature_pgo() ? '+' : '-',
              feature_ime() ? '+' : '-',
              feature_graphemes() ? '+' : '-',
-             feature_assertions() ? '+' : '-');
+             feature_assertions() ? '+' : '-',
+             feature_builtin_wcwidth() ? '+' : '-');
     return buf;
 }