Use the standard gen_snapshot target unless the platform requires host_targeting_host

lib/snapshot/BUILD.gn

@@ -20,12 +20,14 @@ copy("generate_dart_ui") {
 }
 
 compiled_action("generate_snapshot_bin") {
-  # By default Dart will create a 32-bit gen_snapshot host binary if the target
-  # platform is 32-bit.  Override this to create a 64-bit gen_snapshot for x86
-  # targets because some host platforms may not support 32-bit binaries.
-  tool = "//third_party/dart/runtime/bin:gen_snapshot_host_targeting_host"
   if (target_cpu == "x86" && host_os == "linux") {
+    # By default Dart will create a 32-bit gen_snapshot host binary if the target
+    # platform is 32-bit.  Override this to create a 64-bit gen_snapshot for x86
+    # targets because some host platforms may not support 32-bit binaries.
+    tool = "//third_party/dart/runtime/bin:gen_snapshot_host_targeting_host"
     toolchain = "//build/toolchain/$host_os:clang_x64"
+  } else {
+    tool = "//third_party/dart/runtime/bin:gen_snapshot"
   }
 
   if ((is_fuchsia || is_fuchsia_host) && !using_fuchsia_sdk) {