[XRay] Implement `llvm-xray extract`, start of the llvm-xray tool
Usage:
llvm-xray extract <object file> [-o <filename or '-'>]
The tool gets the XRay instrumentation map from an object file and turns
it into YAML. We first support ELF64 sleds on x86_64 binaries, with
provision for supporting other supported platforms and formats later.
This is the first of a many-part change to fully implement the
`llvm-xray` tool.
We also define a subcommand registration and dispatch mechanism to be
used by other further subcommand implementations for llvm-xray.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285155 91177308-0d34-0410-b5e6-96231b3b80d8
19 files changed