Fix "qmake -spec foo" call for cross builds

In a cross built Qt, for example Qt for Android, calling "qmake -spec
android-clang" led to an error message:
    "Could not find qmake spec '-qtconf'."

This happened, because:
- the qmake in Qt for Android is a wrapper script that calls
  "qmake -qtconf qt_target.conf -spec android-clang"
- the first stage of command line argument handling in qmake garbled the
  call to "qmake -spec -qtconf qt_target.conf android-clang"

We do not modify the order of arguments anymore.

Instead, we skip the "-qtconf <file>" arguments in the first argument
handling stage that is supposed to determine qmake's modus
operandi (like -project or -query).

This amends commit 661b586a69740bd9a1791622f8b238d290ebe00d.

Fixes: QTBUG-93079
Task-number: QTBUG-85136
Change-Id: I12ec25b17d64c00be2a3904b7c4a975b781500a0
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
(cherry picked from commit 63a812b85191c9cfe0704d400df86ce7961dea12)

qmake/option.cpp

@@ -403,8 +403,9 @@ Option::init(int argc, char **argv)
         for (int i = 1; i < argc; i++)
             args << QString::fromLocal8Bit(argv[i]);
 
-        while (!args.isEmpty()) {
-            QString opt = args.at(0);
+        qsizetype idx = 0;
+        while (idx < args.size()) {
+            QString opt = args.at(idx);
             if (opt == "-project") {
                 Option::recursive = true;
                 Option::qmake_mode = Option::QMAKE_GENERATE_PROJECT;
@@ -421,15 +422,15 @@ Option::init(int argc, char **argv)
             } else if (opt == "-makefile") {
                 Option::qmake_mode = Option::QMAKE_GENERATE_MAKEFILE;
             } else if (opt == "-qtconf") {
-                if (args.length() >= 3) {
-                    // Move the argument following "-qtconf <file>" in front and check again.
-                    args.prepend(args.takeAt(2));
-                    continue;
-                }
+                // Skip "-qtconf <file>" and proceed.
+                ++idx;
+                if (idx + 1 < args.length())
+                    ++idx;
+                continue;
             } else {
                 break;
             }
-            args.takeFirst();
+            args.takeAt(idx);
             break;
         }