[general] moving ios and android project under ./platform folder

platform/qt/src/string_stdlib.cpp

@@ -0,0 +1,24 @@
+#include <mbgl/util/platform.hpp>
+
+#include <QByteArray>
+#include <QString>
+
+#include <string>
+
+namespace mbgl {
+namespace platform {
+
+std::string uppercase(const std::string& str) {
+    auto upper = QString::fromUtf8(str.data(), str.length()).toUpper().toUtf8();
+
+    return std::string(upper.constData(), upper.size());
+}
+
+std::string lowercase(const std::string& str) {
+    auto lower = QString::fromUtf8(str.data(), str.length()).toLower().toUtf8();
+
+    return std::string(lower.constData(), lower.size());
+}
+
+} // namespace platform
+} // namespace mbgl