[Dotnet Mixed Mode] RIDER-131427. Delegate pausing to the low-level session until the high-level session is ready

GitOrigin-RevId: 7fb072e2e06b1cf8b25ab4a9bae3e9072bb8952f

platform/xdebugger-impl/src/com/intellij/xdebugger/impl/mixedmode/XMixedModeCombinedDebugProcess.kt

@@ -115,6 +115,11 @@ class XMixedModeCombinedDebugProcess(
   }
 
   override fun startPausing() {
+    if (!session.isMixedModeHighProcessReady) {
+      low.startPausing()
+      return
+    }
+
     stateMachine.set(PauseRequested)
   }