* [build] Add "all-libsimulators" target to build all simulator flavors at once. * [build] Refine the "all simulators" target setup and deal with GNU 'make' parallelism issue (ninja=faster); rename to "all-simu-libs".
* [build] Add "all-libsimulators" target to build all simulator flavors at once. * [build] Refine the "all simulators" target setup and deal with GNU 'make' parallelism issue (ninja=faster); rename to "all-simu-libs".