Debugger: FilePath-ify .so libs handling

Side-effect is the stabilization of the order in which the paths are
passed to the debugger (was random, before).

Change-Id: I2dba3ae6f2feef57b26eab93dee0903ee2f93dde
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/debugger/gdb/gdbengine.cpp

@@ -4369,7 +4369,8 @@ void GdbEngine::setupInferior()
     //        postCommand("set architecture " + remoteArch);
         if (!rp.solibSearchPath.isEmpty()) {
             DebuggerCommand cmd("appendSolibSearchPath");
-            cmd.arg("path", rp.solibSearchPath);
+            for (const FilePath &path : rp.solibSearchPath)
+                cmd.arg("path", path);
             cmd.arg("separator", HostOsInfo::pathListSeparator());
             runCommand(cmd);
         }