[vm/nnbd/tests] Fix service/process_service_test for dartkp-weak-asserts config

This test was launching sub-processes without passing
Platform.executableArguments. In dartkp-weak-asserts mode AOT
snapshot is created with assertions enabled and it doesn't work if
--enable-asserts is not passed to dart_precompiled_runtime.

The fix is to always pass Platform.executableArguments to Dart
sub-processes.

Change-Id: I24511b16c447e21e75ad4b77396963616bef18d9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/142707
Reviewed-by: Ben Konyi <bkonyi@google.com>
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Markov <alexmarkov@google.com>
diff --git a/runtime/observatory/tests/service/process_service_test.dart b/runtime/observatory/tests/service/process_service_test.dart
index 02e71fc..ced9326 100644
--- a/runtime/observatory/tests/service/process_service_test.dart
+++ b/runtime/observatory/tests/service/process_service_test.dart
@@ -19,7 +19,11 @@
 Future setupProcesses() async {
   var dir = await io.Directory.systemTemp.createTemp('file_service');
 
-  var args = ['--pause_isolates_on_start', io.Platform.script.toFilePath()];
+  var args = [
+    ...io.Platform.executableArguments,
+    '--pause_isolates_on_start',
+    io.Platform.script.toFilePath(),
+  ];
   var process1;
   var process2;
   var process3;
@@ -57,7 +61,8 @@
             await stdin.drain();
           }
           ''');
-      process3 = await io.Process.start(dartJITBinary, [codeFilePath]);
+      process3 = await io.Process.start(
+          dartJITBinary, [...io.Platform.executableArguments, codeFilePath]);
     } catch (e) {
       closeDown();
       throw e;