LoongArch: Fix incorrect display of FDEs address ranges when using objdump -Wf

When parsing FDEs in `.eh_frame` using `objdump -Wf`, it is necessary to
resolve `BFD_RELOC_LARCH_32_PCREL` to determine the address ranges of
the FDEs. Set the `pcrel_offset` field of `BFD_RELOC_LARCH_32_PCREL` to
help `objdump` correctly compute the address ranges of the FDEs.

Apply the same modification to BFD_RELOC_LARCH_64_PCREL.
4 files changed