Ensure 'interrupt' signal is fully sent before 'disconnect'

While this change does not wait for the target to be paused
it slightly slows down how long after interrupt is sent that
disconnect is sent.

See also eclipse-cdt-cloud#295

src/GDBTargetDebugSession.ts

@@ -535,9 +535,18 @@ export class GDBTargetDebugSession extends GDBDebugSession {
                 this.serialPort.close();
 
             if (this.targetType === 'remote') {
-                if (this.gdb.getAsyncMode() && this.isRunning)
-                    this.gdb.sendCommand('interrupt');
-                await this.gdb.sendCommand('disconnect');
+                if (this.gdb.getAsyncMode() && this.isRunning) {
+                    // See #295 - this use of "then" is to try to slightly delay the
+                    // call to disconnect. A proper solution that waits for the
+                    // interrupt to be successful is needed to avoid future
+                    // "Cannot execute this command while the target is running"
+                    // errors
+                    this.gdb
+                        .sendCommand('interrupt')
+                        .then(() => this.gdb.sendCommand('disconnect'));
+                } else {
+                    await this.gdb.sendCommand('disconnect');
+                }
             }
 
             await this.gdb.sendGDBExit();