[llvm] Use -place-safepoints in JIT mode too (mono/mono#17116)

[llvm] Use -place-safepoints in JIT mode too (mono/mono#17116)

* always use -place-safepoints pass in JIT mode

* ignore loaded llvm

* remove gc.safepoint_poll after optimizations

* fix typo

* cleanup

* cleanup

* cleanup

* cleanup

* Do not emit safepoints on entry thus simple functions (without calls and loops) won't have them at all

* Undo  -spp-no-entry=true

* fix failing tests

* do not emit sp in Allocators

Commit migrated from https://github.com/mono/mono/commit/dc4a7f5ed7094a586cee28c4f9987c40b4f2cea5