Teach sanitizer about NetBSD specific ioctl(2) calls

Summary:
Introduce handling of 1200 NetBSD specific ioctl(2) calls.
Over 100 operations are disabled as unavailable or conflicting
with the existing ones (the same operation number).

Add a script that generates the rules to detect ioctls on NetBSD.
The generate_netbsd_ioctls.awk script has been written
in NetBSD awk(1) (patched nawk) and is compatible with gawk.

Generate lib/sanitizer_common/sanitizer_interceptors_ioctl_netbsd.inc
with the awk(1) script.

Update sanitizer_platform_limits_netbsd accordingly to add the needed
definitions.

Sponsored by <The NetBSD Foundation>

Reviewers: joerg, vitalybuka, eugenis, dvyukov

Reviewed By: vitalybuka

Subscribers: kubamracek, llvm-commits, mgorny, fedor.sergeev, #sanitizers

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D41636

llvm-svn: 325212