incomplete handling of versioned links of tools in cross builds

On Linux, it's expected that user facing tools have versioned links in a prefix build. For example, there should be /usr/bin/qmake and a hard link /usr/bin/qmake6.

In cross-builds, we create wrapper scripts for tools, e.g. /opt/android-qt/bin/qmake that calls /usr/bin/qmake of the host Qt installation.

1. The wrapper script should call the versioned link instead, if available.
2. There should be a versioned link for the wrapper script itself.