Add SunOS case statement to num_cpu_cores

plugins/python-build/bin/python-build

@@ -155,8 +155,11 @@ num_cpu_cores() {
   Darwin | *BSD )
     num="$(sysctl -n hw.ncpu 2>/dev/null || true)"
     ;;
+  SunOS )
+    num="$(getconf NPROCESSORS_ONLN 2>/dev/null)"
+    ;;
   * )
-    num="$({ getconf _NPROCESSORS_ONLN || getconf NPROCESSORS_ONLN ||
+    num="$({ getconf _NPROCESSORS_ONLN ||
              grep -c ^processor /proc/cpuinfo; } 2>/dev/null)"
     num="${num#0}"
     ;;