[kernel] Move unittest.h to include/lib/unittest/

Move unittest.h deeper in the tree so include statements will say:

Change-Id: I85cb027a53530cd2003d813f004aaea3509f9f40

[kernel][unittest] Remove unused "void* context" argument from test cases

This argument is always NULL.

This argument was part of an init/cleanup feature that was unused and
that was removed.

Change-Id: I997a268be10c6837b2d7529fb92c2df2e3bab814

[kernel][unittest] Remove unused init/cleanup function parameters

None of the in-kernel test cases provide init or cleanup functions.
They all pass NULL to UNITTEST_END_TESTCASE() for those parameters, so
we can remove those parameters. Note that unittest.c wasn't actually
using the cleanup function.

Change-Id: I0332bc5c870deec8a021f543ec2c31ef95c30d0f

[x86] Run clang-format

This converts a bunch of the old LK style to the newer style.

Change-Id: I0f9dfc6b2b9b30b7630dc1e2271e8da815edd1d8

[arch][mmu] Rename Map to MapContiguous

This is prep work for adding support for adding a non-contiguous map.

ZX-1424

Change-Id: I63a557a884cfe496cfee2fa58e9f9ec17ba18b8e

[kernel][status][arch] Use zx_status_t throughout kernel/arch

Change-Id: I051aaaee84c6e7776b0054171f8d69320d812fcb

[zx] Rename bug references from MG-nnn to ZX-nnn

Change-Id: I07b0ee32bd7e8cc08e344896352c156b3b420349

[zx] Magenta -> Zircon

The Great Renaming is here!

Change-Id: I3229bdeb2a3d0e40fb4db6fec8ca7d971fbffb94

[kernel][vm] move kernel/kernel/vm to just kernel/vm

Change-Id: I8f724a9f8a61415712661d1fdd3dc4e1c70cf620

[kernel][vm] Remove ArchVmAspace::GetInnerAspace.

The arch_aspace_t structure is still being used internally by the
implementations but it's no longer being publicly exposed.

Change-Id: If7bcd1049ec9c7213ff6eac487f7f9d2fb5064bb

[kernel][mmu] account for page tables per aspace

MG-875 #done

Change-Id: I6ea5308405bd192ada2f10d7be650c943b40d4e9

[kernel][vm] Implement {X86|Arm}ArchVmAspace.

Add distinct ArchVmAspace implementations for each architecture and
convert the old 'arch_mmu_*' functions to use static linkage.

VmAspace still resolves to a single ArchVmAspace implementation at
compile-time.

Change-Id: I347ec0d88634295fd5945c7a72c2f950a6053fdc

[kernel][vm] objectify the mmu layer by adding a simple wrapper object

This just adds a wrapper object around the arch_mmu routines and
switches the high level api to an object oriented model. Subsequent
changes will remove the wrapper and have the two arches implement the
objects directly.

Change-Id: I5ce0d28db5612f4fbc9e0c87d2f6b22dcd09a3f1

[kernel][arch][x86] Use the new MX_ERR_* and MX_OK names

The hypervisor-related files were done in a prior CL.

Change-Id: I6d02e7f8e68fd1775e1d021ad66b9aa8251335e6

[arch][x86] remove kernel x86-32 code and some top level defines in user space

Change-Id: Ib557acd8ca3dea4e7e8b60a29d1ced9d2343cbc8

[kernel][mmu] switch the low level mmu api to returning status_t instead of int

In the case of map/unmap, optionally return the count of pages mapped/unmapped.

Change-Id: I216b030c309b4a457688bedb1ce4bf99359f94d3

[kernel][style] Use nullptr rather than NULL in kernel C++ code

Change-Id: I7feea6a42c00531be28a98c820b2c234484bfe3b

[x86][mmu] Fix bug related to unmapping large demand paged regions

If a demand-paged region of size >=2MB was created, and it was not
aligned to 2MB, and it straddle a 1GB boundary, crashing without
mapping any pages into it would cause misaccounting to occur in
the MMU code, resulting in an assert firing.

The same misaccounting could cause pages to not be unmapped when
requested.

MG-315 #done

Change-Id: I7526eb370b4aba3671c87d78681018f62ba95e26