Since the code is generated unconditionally, using a DCHECK to check
that shared RO heap is enabled breaks builds with
v8_enable_shared_ro_heap set to false, this patch turns that into a
CSA_DCHECK so it only crashes when V8 actually attempts to store into
a shared struct while the RO heap isn't shared at run time.

Refs: https://github.com/nodejs/node/pull/42115
Bug: v8:12547
Change-Id: I30d9a02b98a0b647097125c0a9d141e40d6348cc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3561598Reviewed-by: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Joyee Cheung <joyee@igalia.com>
Cr-Commit-Position: refs/heads/main@{#79756}