Doxygen doc used to look for source files in the source root directory
only. We now use `git ls-files` to figure out which files need to be
part of the documentation.
* Convert ptcdump.cpp to use streams and export more fine-grained functions
* Add documentation to ptcdump.h
* Create metadata for the original instruction when a
PTC_INSTRUCTION_op_debug_insn_start instruction is met.