[wasm] Guard against huge code allocations

If a single background thread generates more code than
{kMaxCodeSpaceSize}, we cannot add them as one chunk. This CL adds a
CHECK to guard against that. If we find that this CHECK is hit in the
wild, we need to fix this for real.

R=ahaas@chromium.org

Bug: v8:11339
Change-Id: I549ecd79747bdf14a65b297c01779953e053abf2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2643382
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72247}

src/wasm/wasm-code-manager.cc

@@ -1912,6 +1912,11 @@ std::vector<std::unique_ptr<WasmCode>> NativeModule::AddCompiledCode(
       code_allocator_.AllocateForCode(this, total_code_space);
   // Lookup the jump tables to use once, then use for all code objects.
   auto jump_tables = FindJumpTablesForRegion(base::AddressRegionOf(code_space));
+  // If we happen to have a {total_code_space} which is bigger than
+  // {kMaxCodeSpaceSize}, we would not find valid jump tables for the whole
+  // region. If this ever happens, we need to handle this case (by splitting the
+  // {results} vector in smaller chunks).
+  CHECK(jump_tables.is_valid());
 
   std::vector<std::unique_ptr<WasmCode>> generated_code;
   generated_code.reserve(results.size());