iOS does not allow you to run any sort of non-apple just-in-time compiler (there is no public API to get executable mmaped pages to be precise), so a no go, you cannot.
It's more than that: nothing outside of the built-in applications is allowed to allocated executable memory at all. You can't even use JSC's JIT (i.e., that of Apple's JS engine) in third-party applications.
> You can't even use JSC's JIT (i.e., that of Apple's JS engine) in third-party applications.
Although this very specific one may get fixed through remote views, which apple is currently toying with (a webview would live in its own "webview process" and thus embedded webview could finally get native JIT-ed speeds)