Add missing i-cache flush in JumpTablePatchingStress test.

Change-Id: I208c8189bded5dfc4fd997cac6a41acc73bf31ab
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1725620Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
Cr-Commit-Position: refs/heads/master@{#62981}

test/cctest/wasm/test-jump-table-assembler.cc

@@ -134,6 +134,7 @@ Address GenerateJumpTableThunk(
 
   CodeDesc desc;
   masm.GetCode(nullptr, &desc);
+  FlushInstructionCache(buffer, desc.instr_size);
   return reinterpret_cast<Address>(buffer);
 }