[llvm] r239552 - Generalize emitAbsoluteSymbolDiff.

[Rafael Espíndola]

> When Duncan was working on this I was wondering if it couldn’t be generalized. I thought the ELF linkers relied on the relocations this would generate eg. for strings in the dwarf_str section. I guess all the strings will be in the same fragment. Without relocations, how can a standard ELF linker rewrite the references to the dwarf_str section when combining multiple input files?

The elf linker needs a relocation if one section refers to another. If
two symbols are in different sections, then they are in different
fragments.

So the case of dwarf_str, only if the two symbols are in dwarf_str
would this function avoid creating the expression.

Cheers,
Rafael