Remove round and rint from jsmath library. NFC

These native versions of these function should be just as efficient
since both of them are based on only `floor` and `ceil` which
themslelves have good native versions.  See js_math.h:

Author: sbc100

system/lib/jsmath.c

@@ -34,21 +34,3 @@ CALL_JS_1_TRIPLE(sqrt, Math.sqrt)
 
 CALL_JS_2_TRIPLE(atan2, Math.atan2)
 CALL_JS_2_TRIPLE(pow, Math.pow)
-
-#define CALL_JS_1_IMPL(cname, type, impl) \
-  EM_JS(type, JS_##cname, (type x), impl); \
-  type cname(type x) { return JS_##cname(x); }
-
-#define CALL_JS_1_IMPL_TRIPLE(cname, impl) \
-  CALL_JS_1_IMPL(cname, double, impl) \
-  CALL_JS_1_IMPL(cname##f, float, impl)
-
-CALL_JS_1_IMPL_TRIPLE(round, {
-  return x >= 0 ? Math.floor(x + 0.5) : Math.ceil(x - 0.5);
-})
-CALL_JS_1_IMPL_TRIPLE(rint,  {
-  function round(x) {
-    return x >= 0 ? Math.floor(x + 0.5) : Math.ceil(x - 0.5);
-  }
-  return (x - Math.floor(x) != .5) ? round(x) : round(x / 2) * 2;
-})