V8 12.0 snapshot version bump breaks embedder upgrades without rebuild
Compatibility boundary at isolate creation V8 12.0 increments the internal snapshot version from 0x1108 to 0x1200, causing Isolate::CreateParams::snapshot_blob validation to reject blobs produced by V8 11.8's mksnapshot . Embedders that ship a prebuilt snapshot_blob.bin and dynamically link against a system V8 library see isolate creation fail with a "Snapsh