Reduce BigInteger construction

The numerator and denominator need to be BigInteger, so request
them as such and reuse those instances. This reduces the number of
BigIntegers constructed to four in the case where they are both
already RubyBignum instances and numerator is less than
denominator, and eight in the worst case where neither of them are
RubyBignum instances and numerator is greater than denominator.

Previously, the best case was six BigInteger (extra from numerator
and denominator being recreated).

Author: headius

core/src/main/java/org/jruby/util/time/TimeArgs.java

@@ -128,16 +128,17 @@ public void initializeTime(ThreadContext context, RubyTime time, DateTimeZone dt
                 if (secondObj instanceof RubyRational subSecond) {
                     if (subSecond.isNegativeNumber(context)) throw argumentError(context, "argument out of range");
 
-                    var numerator = subSecond.getNumerator().asLong(context);
-                    var denominator = subSecond.getDenominator().asLong(context);
-                    if (numerator >= denominator) {
-                        secondsInRational = (int) (numerator / denominator);
-                        numerator = numerator % denominator;
+                    var numerator = subSecond.getNumerator().asBigInteger(context);
+                    var denominator = subSecond.getDenominator().asBigInteger(context);
+                    long subSeconds;
+                    if (numerator.compareTo(denominator) >= 0) {
+                        secondsInRational = numerator.divide(denominator).intValue();
+                        numerator = numerator.mod(denominator);
                     }
 
-                    long subSeconds = BigInteger.valueOf(numerator)
+                    subSeconds = numerator
                             .multiply(RubyTime.TIME_SCALE_BI)
-                            .divide(BigInteger.valueOf(denominator))
+                            .divide(denominator)
                             .longValue();
 
                     millis = subSeconds / 1_000_000;