Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

Make page size dynamic in libkvm for arm64

To allow for a future 16k or 64k page size we need to tell libkvm which
is being used. Add a flag field in unused space in minidumphdr and use
it to signal between the different options.

Reviewed by: markj
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D34548

Chase r350037.

Reported by: jenkins
MFC with: r350037
Sponsored by: The FreeBSD Foundation

Drop "All rights reserved" from my copyright statements.

Reviewed by: rgrimes
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D19485

libkvm: fix build failures

libkvm: add kvm_walk_pages API.

This API allows callers to enumerate all known pages, including any
direct map & kernel map virtual addresses, physical addresses, size,
offset into the core, & protection configured.

For architectures that support direct map addresses, also generate pages
for any direct map only addresses that are not associated with kernel
map addresses.

Fix page size portability issue left behind from previous kvm page table
lookup interface.

Reviewed by: jhb
Sponsored by: Backtrace I/O
Differential Revision: https://reviews.freebsd.org/D12279

Add support to libkvm for reading vmcores from other architectures.
- Add a kvaddr_type to represent kernel virtual addresses instead of
unsigned long.
- Add a struct kvm_nlist which is a stripped down version of struct nlist
that uses kvaddr_t for n_value.
- Add a kvm_native() routine that returns true if an open kvm descriptor
is for a native kernel and memory image.
- Add a kvm_open2() function similar to kvm_openfiles(). It drops the
unused 'swapfile' argument and adds a new function pointer argument for
a symbol resolving function. Native kernels still use _fdnlist() from
libc to resolve symbols if a resolver function is not supplied, but cross
kernels require a resolver.
- Add a kvm_nlist2() function similar to kvm_nlist() except that it uses
struct kvm_nlist instead of struct nlist.
- Add a kvm_read2() function similar to kvm_read() except that it uses
kvaddr_t instead of unsigned long for the kernel virtual address.
- Add a new kvm_arch switch of routines needed by a vmcore backend.
Each backend is responsible for implementing kvm_read2() for a given
vmcore format.
- Use libelf to read headers from ELF kernels and cores (except for
powerpc cores).
- Add internal helper routines for the common page offset hash table used
by the minidump backends.
- Port all of the existing kvm backends to implement a kvm_arch switch and
to be cross-friendly by using private constants instead of ones that
vary by platform (e.g. PAGE_SIZE). Static assertions are present when
a given backend is compiled natively to ensure the private constants
match the real ones.
- Enable all of the existing vmcore backends on all platforms. This means
that libkvm on any platform should be able to perform KVA translation
and read data from a vmcore of any platform.

Tested on: amd64, i386, sparc64 (marius)
Differential Revision: https://reviews.freebsd.org/D3341