conflicting countdowns again

Use the make_foo() intrinsic set/reset routines instead of trying
to manipulate the intrinsics directly.  Previous patch left Dex
down by 1 if stoning caused wounded legs to be fixed, and left
delayed killer allocated if stoning cured sliming or vice versa.

src/do.c

@@ -1882,7 +1882,8 @@ register int timex;
 }
 
 void
-heal_legs()
+heal_legs(how)
+int how; /* 0: ordinary, 1: dismounting steed, 2: limbs turn to stone */
 {
     if (Wounded_legs) {
         if (ATEMP(A_DEX) < 0) {
@@ -1890,7 +1891,11 @@ heal_legs()
             context.botl = 1;
         }
 
-        if (!u.usteed) {
+        /* when mounted, wounded legs applies to the steed;
+           during petrification countdown, "your limbs turn to stone"
+           before the final stages and that calls us (how==2) to cure
+           wounded legs, but we want to suppress the feel better message */
+        if (!u.usteed && how != 2) {
             const char *legs = body_part(LEG);
 
             if ((EWounded_legs & BOTH_SIDES) == BOTH_SIDES)
@@ -1900,7 +1905,7 @@ heal_legs()
             Your("%s %s better.", legs, vtense(legs, "feel"));
         }
 
-        HWounded_legs = EWounded_legs = 0;
+        HWounded_legs = EWounded_legs = 0L;
 
         /* Wounded_legs reduces carrying capacity, so we want
            an encumbrance check when they're healed.  However,
@@ -1912,7 +1917,7 @@ heal_legs()
            it might be immediately contradicted [able to carry
            more when steed becomes healthy, then possible floor
            feedback, then able to carry less when back on foot]. */
-        if (!in_steed_dismounting)
+        if (how == 0)
             (void) encumber_msg();
     }
 }