[mjsunit] Use smaller test array

This might help reduce flaky test results caused by too high memory
consumption due to the large Float32Array in regress-crbug-1057653.js.

Bug: v8:10333
Change-Id: Id99ebb67ebe5a7a730e44cd8967ebbea905ccdc5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2108547Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66836}

test/mjsunit/regress/regress-crbug-1057653.js

@@ -3,6 +3,6 @@
 // found in the LICENSE file.
 
 Object.prototype.length = 3642395160;
-const array = new Float32Array(2**28);
+const array = new Float32Array(2**27);
 
 assertThrows(() => {for (const key in array) {}}, RangeError);