Add llvm-objdump --call-graph-info option to disassemble the binary and parse
the .callgraph section for call graph information.
This patch extracts and prints function entry address to name mapping.
This can be used to annotate function nodes on a reconstructed call
graph. Upcoming patches will add the rest of the functionality (call
site info and .callgraph section parsing).
Patch 2/6: Extract call graph information from binary
Original RFC: https://lists.llvm.org/pipermail/llvm-dev/2021-June/151044.html
Updated RFC: https://lists.llvm.org/pipermail/llvm-dev/2021-July/151739.html
Will these tests break if DenseMap changes its hash function?
We should probably use a sorted map.