[xxx] Adjust read memory value in case of 32-bit ABI only.
[xxx] Detect 64-bit sig-handler.
[xxx] Move 64-bit heuristic stack tracing to the separate function.
[xxx] Print uc_mcontext.pc in the gen-offsets tool.
[xxx] Fix the mips_reg_t definition for 64-bit ABI.
[xxx] Add handling of non-FP stack frames.