[yaml2obj/obj2yaml] - Add support for the SHT_LLVM_CALL_GRAPH_PROFILE section.

This is a LLVM specific section that is well described here:
https://llvm.org/docs/Extensions.html#sht-llvm-call-graph-profile-section-call-graph-profile

This patch teaches yaml2obj and obj2yaml about how to work with it.

Differential revision: https://reviews.llvm.org/D73788