.. and make travis run it.
I renamed check-license-headers.sh to check-style.sh and expanded it so
that it now also checks for the presence of "#pragma once" in .h files.
It also checks the presence of a (single) blank line above and below the
"#pragma once" line.
I also added "#pragma once" to all the files that need it: even the ones
we are not check.
I also added/removed blank lines in order to make the script not fail.
I also ran clang-format on the files I modified.
DWARF line number information, if generated, is stored in the
.debug_line section of an object file.
The information is encoded as instructions for a VM that is defined in
the DWARF specification.
By executing these instructions, we can extract the encoded line number
information.
