std.cfg: Fixed missing attributes of <ctime> (time.h) functions.

cfg/std.cfg

@@ -635,6 +635,7 @@
     </arg>
   </function>
   <function name="clock">
+    <use-retval/>
     <noreturn>false</noreturn>
     <leak-ignore/>
   </function>
@@ -725,6 +726,7 @@
     <leak-ignore/>
     <arg nr="1">
       <not-uninit/>
+      <not-null/>
     </arg>
   </function>
   <function name="difftime">
@@ -2034,6 +2036,7 @@
     <leak-ignore/>
     <arg nr="1">
       <not-uninit/>
+      <not-null/>
     </arg>
   </function>
   <function name="log">
@@ -3541,6 +3544,9 @@
   <function name="time">
     <noreturn>false</noreturn>
     <leak-ignore/>
+    <arg nr="1">
+      <not-uninit/>
+    </arg>
   </function>
   <function name="tmpnam">
     <noreturn>false</noreturn>