Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Remove trailing whitespace from sys/arm/arm

Remove unused cpufunc arm11 and armv6 code. While here only define the
remaining functions in the context we use them in.

Fix unwind-info errors in our hand-written arm assembler code.

We have functions nested within functions, and places where we start a
function then never end it, we just jump to the middle of something else.
We tried to express this with nested ENTRY()/END() macros (which result
in .fnstart and .fnend directives), but it turns out there's no way to
express that nesting in ARM EHABI unwind info, and newer tools treat
multiple .fnstart directives without an intervening .fnend as an error.

These changes introduce two new macros, EENTRY() and EEND(). EENTRY()
creates a global label you can call/jump to just like ENTRY(), but it
doesn't emit a .fnstart. EEND() is a no-op that just documents the
conceptual endpoint that matches up with the same-named EENTRY().

This is based on patches submitted by Stepan Dyatkovskiy, but I made some
changes and added the EEND() stuff, so blame any problems on me.

Submitted by: Stepan Dyatkovskiy <stpworld@narod.ru>

Remove code under PMAP_CACHE_VIVT that is not compiled anymore.

This is for ARMv4/ARMv5 and it doesn't belong in ARMv6 code.

Reviewed by: ian

Add a new cache maintenance function, idcache_inv_all, to the table, and
implementations for each of the chips we support. Most chips up through
armv6 can use the armv4 implementation which has a single coprocessor
opcode for this operation. The rather more complex armv7 implementation
comes from netbsd.

Add an END macro to ARM. This is mostly used to tell gas where the bounds
of the functions are when creating the EABI unwind tables.

Add support for ARM11 cpufunc

Obtained from: NetBSD (partially)