Revert "Make intl/overrides/caching.js more 'robust'"

This reverts commit 4091f2b3.

Reason for revert: Flaky on the bots:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64/builds/21321
https://build.chromium.org/p/client.v8/builders/V8%20Win64/builds/20879
https://build.chromium.org/p/client.v8/builders/V8%20Win64%20-%20msvc/builds/101

Original change's description:
> Make intl/overrides/caching.js more 'robust'
> 
> Bug: None
> Test: intl/overrides/caching
> Cq-Include-Trybots: master.tryserver.v8:v8_linux_noi18n_rel_ng
> Change-Id: Iffd0f58f76d6514924badca18a2112df572e53d2
> Reviewed-on: https://chromium-review.googlesource.com/757945
> Reviewed-by: Adam Klein <adamk@chromium.org>
> Commit-Queue: Jungshik Shin <jshin@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#49334}

TBR=adamk@chromium.org,jshin@chromium.org

Change-Id: Id2fe00089c2bcbc8ecc7958fe13c8a80da733e60
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: None
Cq-Include-Trybots: master.tryserver.v8:v8_linux_noi18n_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/766288Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49336}

test/intl/intl.status

@@ -26,6 +26,10 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 [
+[ALWAYS, {
+  # TODO(jochen): The following test is flaky.
+  'overrides/caching': [PASS, FAIL],
+}],  # ALWAYS
 
 ['variant == wasm_traps', {
   '*': [SKIP],

test/intl/overrides/caching.js

@@ -53,9 +53,7 @@ for (var i = 0; i < 1000; i++) {
 endTime = new Date();
 collatorTime = endTime.getTime() - startTime.getTime();
 
-// Difference is within 20%. collatorTime should be smaller,
-// but it can be noisy. Give an enough margin of error.
-assertTrue(collatorTime < cachedTime * 1.5);
+// Difference is within 20%.
+assertTrue(collatorTime < cachedTime);
 // Non-cached time is much slower, measured to 12.5 times.
 assertTrue(cachedTime < nonCachedTime);
-assertTrue(collatorTime < nonCachedTime);