Inline step operations

[gabrielbosio]

Inline the following functions in vm_core.rs:

• update_fp() (line 153)
• update_ap() (line 172)
• update_pc() (line 190)
• update_registers() (line 217)
• compute_operands() (line 696)

Also in run_context.rs:

• get_ap(), get_fp() (lines 19-24) - create new Relocatable every call
• compute_dst_addr(), compute_op0_addr(), compute_op1_addr()