[sparkplug] Enable short builtin calls by default

... when they are enabled via the GN flag.

Sheriffs: This CL adds ~1.2-1.4Mb of memory overhead per Isolate on
certain configurations and that's expected. This is a temporary fix
until the full solution is implemented.
See the design doc linked to the issue for details.

Bug: v8:11527
Change-Id: Ie59f55050c02fe523e2be890e2a6f74ff3eca1ea
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2784682
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73637}

src/flags/flag-definitions.h

@@ -1546,7 +1546,7 @@ DEFINE_BOOL(experimental_flush_embedded_blob_icache, false,
 #define V8_SHORT_BUILTIN_CALLS_BOOL false
 #endif
 
-DEFINE_BOOL(short_builtin_calls, false,
+DEFINE_BOOL(short_builtin_calls, V8_SHORT_BUILTIN_CALLS_BOOL,
             "Put embedded builtins code into the code range for shorter "
             "builtin calls/jumps if system has >=4GB memory")