Land v8-side changes to switch to v8_current_cpu in the GN build.

gni/v8.gni

Index: gni/v8.gni
diff --git a/gni/v8.gni b/gni/v8.gni
index 4abce0d17689aa47084c8084242cc75acf38902d..8a4b2d792a6ab0ffd4af0da3036b8be82db81958 100644
--- a/gni/v8.gni
+++ b/gni/v8.gni
@@ -2,8 +2,8 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/v8_target_cpu.gni")
 import("//build/config/sanitizers/sanitizers.gni")
+import("//build/config/v8_target_cpu.gni")
 
 declare_args() {
   # Indicate if valgrind was fetched as a custom deps to make it available on