[clang] [llvm] [llvm-objcopy][libObject] Add RISC-V big-endian support (PR #146913)

[Djordje Todorovic via llvm-commits]

djtodoro wrote:

> > Looks good from my point of view, once the remaining formatting comments have been addressed. Probably should have a separate person with RISC-V knowledge take a look at this too though.
> 
> This comment still stands for me.

Thank you @jh7370.

@topperc Do you agree? :)

https://github.com/llvm/llvm-project/pull/146913