* src/vm/jit/powerpc/md.c (md_patch_replacement_point): Added.

* src/vm/jit/powerpc/md.c (md_patch_replacement_point): Added.

* src/vm/jit/powerpc/codegen.c (codegen): Handle replacement points.

* src/vm/jit/powerpc/asmpart.S (asm_replacement_out): Added.
(asm_replacement_in): Likewise.

* src/vm/jit/alpha/codegen.c (codegen): Added missing initialization
of `replacementpoint`.

* src/vm/jit/alpha/asmpart.S (asm_replacement_out): Store PV register.

* src/vm/jit/code.c (code_get_sync_slot_count): Ported to PowerPC.
(code_get_stack_frame_size): Likewise.

* src/vm/jit/replace.c (replace_activate_replacement_point)
(replace_deactivate_replacement_poin): Activated for PowerPC.
(replace_read_value, replace_write_value): Added.
(replace_read_executionstate): Ported to PowerPC, more complete
data type handling.
(replace_write_executionstate): Ported to Ported, more complete
data type handling, fixed missing initialization of `topslot`.
(replace_me): Activated for PowerPC.