Llvm optimizations (#16191)
* [jit] Disable inlining for ThrowHelper methods for non-netcore as well. Add an OP_NOT_REACHED after calls to these methods to let LLVM know they don't return.
* [llvm] Use the cold calling convention instead of the preserveall one, it has the same effect and its better supported.
* [llvm] Call the aot init function using the cold cconv.
* [llvm] Make the condition in the poll function unlikely.
* [llvm] Add a wrapper around the GC poll icall so it can be called with a cold calling convention.
* Move the noreturn check before the code which is shared with calli.