[sandbox] Use the virtual memory cage when the sandbox is enabled

The heap sandbox will rely on the virtual memory cage to protect the
data pointers in ArrayBuffers, TypedArrays, and DataViews.

Bug: v8:10391
Change-Id: Ib0ee352e0eba07dea0fb9e0dc4957cb74d37ba3b
Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3101489Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Samuel Groß <saelo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76361}

BUILD.gn

@@ -397,7 +397,7 @@ if (v8_enable_heap_sandbox == "") {
   v8_enable_heap_sandbox = false
 }
 if (v8_enable_virtual_memory_cage == "") {
-  v8_enable_virtual_memory_cage = false
+  v8_enable_virtual_memory_cage = v8_enable_heap_sandbox
 }
 if (v8_enable_short_builtin_calls == "") {
   v8_enable_short_builtin_calls =
@@ -490,6 +490,9 @@ assert(!v8_enable_heap_sandbox || v8_enable_pointer_compression,
 assert(!v8_enable_heap_sandbox || !v8_enable_external_code_space,
        "V8 Heap Sandbox is not compatible with external code space YET")
 
+assert(!v8_enable_heap_sandbox || v8_enable_virtual_memory_cage,
+       "The Heap Sandbox requires the virtual memory cage")
+
 assert(
     !v8_enable_virtual_memory_cage || v8_enable_pointer_compression_shared_cage,
     "V8 VirtualMemoryCage requires the shared pointer compression cage")