[test] skip peephole tests on big endian

tests where moved from cctest to unittests under this cl:
https://crrev.com/c/3607370

Bug: v8:12781
Change-Id: If625e0dda51034e731c5e7fe87d591dce9804888
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3611182Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Milad Farazmand <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/main@{#80227}

test/cctest/cctest.status

@@ -311,8 +311,6 @@
   # BUG(v8:12505). Tests which share Wasm memory buffer with Js Typed arrays.
   'test-api/WasmI32AtomicWaitCallback': [SKIP],
   'test-api/WasmI64AtomicWaitCallback': [SKIP],
-  # Peephole optimization not supported on big-endian machines.
-  'test-regexp/Peephole*': [SKIP],
 }],  # 'byteorder == big'
 
 ##############################################################################

test/unittests/unittests.status

@@ -141,4 +141,10 @@
   'UnifiedHeapTest.FindingV8ToBlinkReference': [SKIP],
 }], # third_party_heap
 
+##############################################################################
+['byteorder == big', {
+  # Peephole optimization not supported on big-endian machines.
+  'RegExpTest.Peephole*': [SKIP],
+}],  # 'byteorder == big'
+
 ]