[Mips] Document Mips Backend Relocation Principles

This revision documents the combination of C++ and table-gen code that
handles relocations and addresses.

Thanks for Simon Dardis for the careful reviews.

Differential Revision: https://reviews.llvm.org/D31628


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300986 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed