Hook up SDL_acos and SDL_asin properly.

src/libm/s_atan.c

@@ -113,28 +113,3 @@ double atan(double x)
 }
 libm_hidden_def(atan)
 
-double SDL_acos(double val)
-{
-    double result;
-    if (val == -1.0) {
-        result = M_PI;
-    } else {
-        result = SDL_atan(SDL_sqrt(1.0 - val * val) / val);
-        if (result < 0.0)
-        {
-            result += M_PI;
-        }
-    }
-    return result;
-}
-
-double SDL_asin(double val)
-{
-    double result;
-    if (val == -1.0) {
-        result = -(M_PI / 2.0);
-    } else {
-        result = (M_PI / 2.0) - SDL_acos(val);
-    }
-    return result;
-}