Unify the header guard style and replace the inconsistent include guards
with #pragma once.
The #pragma once is widely and very well supported in all compilers that
BIND 9 supports, and #pragma once was already in use in several new or
refactored headers.
Using simpler method will also allow us to automate header guard checks
as this is simpler to programatically check.
For reference, here are the reasons for the change taken from
Wikipedia[1]:
> In the C and C++ programming languages, #pragma once is a non-standard
> but widely supported preprocessor directive designed to cause the
> current source file to be included only once in a single compilation.
>
> Thus, #pragma once serves the same purpose as include guards, but with
> several advantages, including: less code, avoidance of name clashes,
> and sometimes improvement in compilation speed. On the other hand,
> #pragma once is not necessarily available in all compilers and its
> implementation is tricky and might not always be reliable.
1. https://en.wikipedia.org/wiki/Pragma_once
The last remaining defines needed for platforms without NAME_MAX and
PATH_MAX (I'm looking at you, GNU Hurd) were moved to isc/dir.h where
it's prevalently used.
* Disallow compression pointers in names as we are not
reading from a packet and as a result length checks fail.
* Increase totext buffer size as fuzzer ran out of space on
big bitmaps.
* NUL terminate totext to make fault diagnosis easier.
* Add debugging messages to make fault diagnosie easier.
In this commit, the simple fuzzing tests for the isc_lex_gettoken() and
isc_lex_getmastertoken() functions have been added.
As part of this commit, the initialization has been moved from fuzz.h
constructor/destructor to LLVMFuzzerInitialize() in each fuzz test. The
main.c of no-fuzzing and AFL modes have been modified to run the
LLVMFuzzerInitialize() at the start of the main() function mimicking
the libfuzzer mode of operation.
