qbs build: Suppress more warnings

Amends d08e5c33ff.

Change-Id: Ic842dda51b21427e1989190b44508d54aa1e7120
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

tests/auto/extensionsystem/plugin.qbs

@@ -1,5 +1,5 @@
-import qbs
 import qbs.FileInfo
+import qbs.Utilities
 import QtcFunctions
 
 DynamicLibrary {
@@ -12,6 +12,15 @@ DynamicLibrary {
     targetName: QtcFunctions.qtLibraryName(qbs, name.split('_')[1])
     destinationDirectory: project.buildDirectory + '/'
                           + FileInfo.relativePath(project.ide_source_tree, sourceDirectory)
+    cpp.cxxFlags: {
+        var flags = [];
+        if (qbs.toolchain.contains("clang")
+                && Utilities.versionCompare(cpp.compilerVersion, "10") >= 0) {
+             // Triggers a lot in Qt.
+            flags.push("-Wno-deprecated-copy", "-Wno-constant-logical-operand");
+        }
+        return flags;
+    }
     cpp.rpaths: [
         project.buildDirectory + "/" + qtc.libDirName + "/qtcreator",
         project.buildDirectory + "/" + qtc.libDirName + "/qtcreator/plugins"