Designer: Update C++ code model on an object name change in designer

We try to locate the old symbol name in the generated ui header and
rename the symbol in the background.

Task-number: QTCREATORBUG-1179
Change-Id: Iaf68e3922cd728cbc87d0dc97125e34b8bdaa6be
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/cmakeprojectmanager/cmakebuildsystem.cpp

@@ -1401,4 +1401,11 @@ void CMakeBuildSystem::runGenerator(Id id)
     proc->start();
 }
 
+ExtraCompiler *CMakeBuildSystem::extraCompilerForSource(const Utils::FilePath &source)
+{
+    return Utils::findOrDefault(m_extraCompilers, [source](ExtraCompiler *ec) {
+        return ec->source() == source;
+    });
+}
+
 } // CMakeProjectManager::Internal