Fix no_std build.

src/packages/pkg_std.rs

@@ -5,6 +5,7 @@ use super::map_basic::BasicMapPackage;
 use super::math_basic::BasicMathPackage;
 use super::pkg_core::CorePackage;
 use super::string_more::MoreStringPackage;
+#[cfg(not(feature = "no_std"))]
 use super::time_basic::BasicTimePackage;
 
 use crate::def_package;
@@ -16,6 +17,7 @@ def_package!(crate:StandardPackage:"_Standard_ package containing all built-in f
     BasicArrayPackage::init(lib);
     #[cfg(not(feature = "no_object"))]
     BasicMapPackage::init(lib);
+    #[cfg(not(feature = "no_std"))]
     BasicTimePackage::init(lib);
     MoreStringPackage::init(lib);
 });