arm:refactor move pagetable to the common directory.

Change-Id: Ic3178241f86156f729f016017f61017653ddbd23
arm:disable filemmap.

We currently have a few of the POSIX tests failing because filemmap
is enabled by default. The working assumption is that these program
pass a pointer to the file server that points to a not yet loaded
data segment. When the file server tries to access that data it
therefore generates a pagefault and a call to itself it can not
handle because it is unable to first return the current call.

Change-Id: Ic1a2d9cd0a542bd950e2b08accb61cfe2855c5a3
arm:indenting

Change-Id: I2f8f664fa4c66649db8981e58e6bb7a6f533df5a
VM bugfix & regression test

The bug in the offset correction code for the 'shrink region from
below' case can easily case an assert(foundregion->offset == offset)
to trigger (if the blocks are touched afterwards, e.g. on fork())
as the offsets become wrong. This commit is a fix & regression test.

Change-Id: I28ed403e3891362a2dea674a49e786d3450d2983