Test exact precision for DurationFormat

`Intl.DurationFormat` is currently spec'ed to use unlimited precision.

See: https://github.com/tc39/proposal-intl-duration-format/issues/157

test/intl402/DurationFormat/prototype/format/precision-exact-mathematical-values.js

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+// Copyright (C) 2023 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-Intl.DurationFormat.prototype.format
+description: >
+  PartitionDurationFormatPattern computes on exact mathematical values.
+info: |
+  PartitionDurationFormatPattern ( durationFormat, duration )
+  ...
+  4. While done is false, repeat for each row in Table 1 in order, except the header row:
+    ...
+    j. If unit is "seconds", "milliseconds", or "microseconds", then
+      i. If unit is "seconds", then
+        1. Let nextStyle be durationFormat.[[MillisecondsStyle]].
+      ...
+      iv. If nextStyle is "numeric", then
+        1. If unit is "seconds", then
+          a. Set value to value + duration.[[Milliseconds]] / 10^3 + duration.[[Microseconds]] / 10^6 + duration.[[Nanoseconds]] / 10^9.
+    ...
+    l. If value is not 0 or display is not "auto", then
+      ii. If style is "2-digit" or "numeric", then
+        ...
+        7. Let parts be ! PartitionNumberPattern(nf, value).
+        ...
+
+locale: [en-US]
+includes: [testIntl.js]
+features: [Intl.DurationFormat]
+---*/
+
+const durations = [
+  // 10000000 + (1 / 10^9)
+  // = 10000000.000000001
+  {
+    seconds: 10_000_000,
+    nanoseconds: 1,
+  },
+
+  // 9007199254740991 + (9007199254740991 / 10^3) + (9007199254740991 / 10^6) + (9007199254740991 / 10^9)
+  // = 9.016215470202185986731991 × 10^15
+  {
+    seconds: Number.MAX_SAFE_INTEGER,
+    milliseconds: Number.MAX_SAFE_INTEGER,
+    microseconds: Number.MAX_SAFE_INTEGER,
+    nanoseconds: Number.MAX_SAFE_INTEGER,
+  },
+  {
+    seconds: Number.MIN_SAFE_INTEGER,
+    milliseconds: Number.MIN_SAFE_INTEGER,
+    microseconds: Number.MIN_SAFE_INTEGER,
+    nanoseconds: Number.MIN_SAFE_INTEGER,
+  },
+
+  // 1 + (2 / 10^3) + (3 / 10^6) + (9007199254740991 / 10^9)
+  // = 9.007200256743991 × 10^6
+  {
+    seconds: 1,
+    milliseconds: 2,
+    microseconds: 3,
+    nanoseconds: Number.MAX_SAFE_INTEGER,
+  },
+
+  // 9007199254740991 + (10^3 / 10^3) + (10^6 / 10^6) + (10^9 / 10^9)
+  // = 9007199254740991 + 3
+  // = 9007199254740994
+  {
+    seconds: Number.MAX_SAFE_INTEGER,
+    milliseconds: 10 ** 3,
+    microseconds: 10 ** 6,
+    nanoseconds: 10 ** 9,
+  },
+
+  // ~1.7976931348623157e+308 / 10^9
+  // = ~1.7976931348623157 × 10^299
+  {
+    seconds: 0,
+    milliseconds: 0,
+    microseconds: 0,
+    nanoseconds: Number.MAX_VALUE,
+  },
+];
+
+const df = new Intl.DurationFormat("en", {style: "digital"});
+
+for (let duration of durations) {
+  let expected = formatDurationFormatPattern(duration, "digital");
+  assert.sameValue(
+    df.format(duration),
+    expected,
+    `Duration is ${JSON.stringify(duration)}`
+  );
+}