[snapshot] Disable snapshot compression on desktop

Snapshot decompression for new isolates or new context is roughly 10%
of the time. Unlike on mobile, we don't need to compress the snapshot
on desktop where we can live with a 400KiB regression.

Bug: v8:12195, chromium:1270752
Change-Id: Ie4b307125f5df3d94374d5295b06c457ab6e8c24
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3275554
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78087}

BUILD.gn

@@ -275,8 +275,10 @@ declare_args() {
   # Generate comments describing the Torque intermediate representation.
   v8_annotate_torque_ir = false
 
-  # Disable all snapshot compression.
-  v8_enable_snapshot_compression = true
+  # Enable snapshot compression (enabled by default for desktop) devices.
+  v8_enable_snapshot_compression =
+      target_os == "android" || target_os == "chromeos" ||
+      target_os == "fuchsia"
 
   # Enable control-flow integrity features, such as pointer authentication for
   # ARM64.