[regexp] Skip regression test for experimental engine.

The expected exception in this regression test is thrown due to a
limitation in the IrRegExp engine.
The experimental engine is unaffected and won't throw.

Bug: v8:11363
Change-Id: If37d86f5d4494b40c47ecc5e5bc4f86fda30389c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2699251
Auto-Submit: Patrick Thier <pthier@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72806}

test/mjsunit/regress/regress-1166138.js

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// Flags: --no-enable-experimental-regexp-engine
+
 let badregexp =  "(?:" +  " ".repeat(32768*2)+  ")*";
 reg = RegExp(badregexp);
 assertThrows(() => reg.test(), SyntaxError);