test: avoid flaky restart sync in debugger exceptions test

Author: inoway46

test/parallel/test-debugger-exceptions.js

@@ -27,7 +27,9 @@ const path = require('path');
       await cli.waitFor(/disconnect/);
 
       // Next run: With `breakOnException` it pauses in both places.
-      await cli.stepCommand('r');
+      await cli.command('r');
+      await cli.waitFor(/Debugger attached\./);
+      await cli.waitForPrompt();
       await cli.waitForInitialBreak();
       assert.deepStrictEqual(cli.breakInfo, { filename: script, line: 1 });
       await cli.command('breakOnException');
@@ -38,15 +40,19 @@ const path = require('path');
 
       // Next run: With `breakOnUncaught` it only pauses on the 2nd exception.
       await cli.command('breakOnUncaught');
-      await cli.stepCommand('r'); // Also, the setting survives the restart.
+      await cli.command('r'); // Also, the setting survives the restart.
+      await cli.waitFor(/Debugger attached\./);
+      await cli.waitForPrompt();
       await cli.waitForInitialBreak();
       assert.deepStrictEqual(cli.breakInfo, { filename: script, line: 1 });
       await cli.stepCommand('c');
       assert.ok(cli.output.includes(`exception in ${script}:9`));
 
       // Next run: Back to the initial state! It should die again.
       await cli.command('breakOnNone');
-      await cli.stepCommand('r');
+      await cli.command('r');
+      await cli.waitFor(/Debugger attached\./);
+      await cli.waitForPrompt();
       await cli.waitForInitialBreak();
       assert.deepStrictEqual(cli.breakInfo, { filename: script, line: 1 });
       await cli.command('c');