[PATCH 0/5] build: cross compile wayland

[mchalain [marc.chalain@gmail.com]]

In cross compile, the "host" running the libraries, is different to the "build" machine running the compiler. In this case wayland-scanner is a part of the "build" tools and not a part of the "host" tools.
Autotool and "configure" provide the "--host", "--target" and "--build" options. When the values of "--host" and "--build" are different, the build is a cross compile, and in this case the compiler of "host" tools (libwayland-client and libwayland-server) has to be different of the compiler of "build" tools (wayland-scanner)
This patches uses ax_cc_for_build to define the compiler of the "build" tools, and uses the definition to build wayland-scanner.