[test] Make pause-on-oom run out of memory faster

Allocate memory more quickly so the test completes faster. (On the ARM
simulator tests with slow asserts and verify-heap, it was taking around
20 minutes).

Change-Id: I6b4d0a4788817c4f996a073cc3fdf8b69d11bc40
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1973731Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65495}

test/inspector/debugger/pause-on-oom.js

@@ -11,7 +11,7 @@ var arr = [];
 var stop = false;
 function generateGarbage() {
   while(!stop) {
-    arr.push(42);
+    arr.push(new Array(1000));
   }
 }
 //# sourceURL=test.js`, 10, 26);