VMUserAddressSpace: Make fAreas an AVLTree.

This is analogous to the AVLTree used for kernel address ranges in
VMKernelAddressSpace. It does not use an additional DoublyLinkedList
however.

Using a binary tree speeds up many operations that previously had to
iterate the area list linearly to find normal and reserved areas,
insertion start points, etc. It especially benefits LookupArea which is
called for every page fault and from area_for() when randomly accessing
different areas as that would make the previously used area hint (i.e.
a one level lookup cache) ineffective.

The overhead of the tree versus the doubly linked list for iteration,
insertion and removal is reasonably small and pales in comparison to
what the linear searches previously took up.

Fixes the lookup performance in #15995.

Change-Id: I48319fe6a2e4327826e90ebca7246c7c419b5218
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2839
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

white space cleanup

* Introduced {malloc,memalign,free}_etc() which take an additional "flags"
argument. They replace the previous special-purpose allocation functions
(malloc_nogrow(), vip_io_request_malloc()).
* Moved the I/O VIP heap to heap.cpp accordingly.
* Added quite a bit of passing around of allocation flags in the VM,
particularly in the VM*AddressSpace classes.
* Fixed IOBuffer::GetNextVirtualVec(): It was ignoring the VIP flag and always
allocated on the normal heap.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35316 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added VMArea subclasses VM{Kernel,User}Area and moved the address space list
link to them.
* VM{Kernel,User}AddressSpace manage the respective VMArea subclass now, and
VMAddressSpace has grown factory methods {Create,Delete}Area.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34493 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduced {malloc,memalign,free}_etc() which take an additional "flags"
argument. They replace the previous special-purpose allocation functions
(malloc_nogrow(), vip_io_request_malloc()).
* Moved the I/O VIP heap to heap.cpp accordingly.
* Added quite a bit of passing around of allocation flags in the VM,
particularly in the VM*AddressSpace classes.
* Fixed IOBuffer::GetNextVirtualVec(): It was ignoring the VIP flag and always
allocated on the normal heap.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35316 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added VMArea subclasses VM{Kernel,User}Area and moved the address space list
link to them.
* VM{Kernel,User}AddressSpace manage the respective VMArea subclass now, and
VMAddressSpace has grown factory methods {Create,Delete}Area.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34493 a95241bf-73f2-0310-859d-f6bbb57e9c96