I understood how to build core and did big testing.
The commit it started with: d148d26 / September 19, 2016
At this moment, dyneric starts working on the iOS 5.1.1, but at the same time the application stops unloading from the RAM and any failure causes the entire system to freeze!!!
The code that is responsible for this is in the frontend/libretro.c file, commented as: āmagic sauce to make the dynarec work on iOSā. After removing this code, the application can be unloaded from RAM. This does not break dynamic recompilation.
Input data and test result is published here: https://github.com/libretro/pcsx_rearmed/issues/495