C1 and C2 JIT compilers generate stack banging code before the code for saving the PC into the frame on PPC64 and s390.
Hence, the PC needs to be picked from the signal context (LR on PPC64 and R14 on s390) to create a correct frame object.

Currently, the top frame can not be checked for reserved stack annotation because the frame doesn't get a PC which points into the nmethod.