changes:
- In ppc_elf_additional_program_headers, modified ret=0 to ret=1 to add an additional
section header for dynamic linking, since we need an additional PT_LOAD for the
separate .text section.
- In ppc_elf_create_got, removed the SEC_CODE flag from the .got section to prevent it
from being moved into the executable section. We do not use -fpic and hence have no
need for the blrl in the .got section.
- In ppc_elf_finish_dynamic_symbol, removed the code that makes _DYNAMIC,
_GLOBAL_OFFSET_TABLE_ and _PROCEDURE_LINKAGE_TABLE_ absolute, since we need them
to be relocatable.
