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

Annotate arm userspace assembler sources stating their tolerance to
the non-executable stack.

Reviewed by: andrew
Sponsored by: The FreeBSD Foundation

Remove __ARM_EABI__ from more places in libc as this is the only ARM ABI
we support.

Teach bits of libc about Thumb. This adds the if-then instructions needed
to handle the ARM conditional execution.

While here fix a bug found by this in the hard-float code, cc is the
opposite of cs. The former is used for 'less than' in floating-point code
and is executed when the C (carry) bit is clear, the latter is used when
greater than, equal, or unordered, and is executed when the C bit is set.

In ARM asm code, ensure that every ENTRY(foo) has a matching END(foo).
The EABI unwind info requires a .fnend for every .fnstart, and newer
binutils will complain about seeing two .fnstart in a row. This change
allows newer tools to compile our code.

Reported by: bapt
Reviewed by: imp

Finish pulling in the NetBSD setjmp/longjmp updates on ARM.

Store/restore the VFP registers in setjmp/longjmp on ARM EABI if VFP is
enabled in the kernel. It checks the hw.floatingpoint sysctl to see if
floating-point is available and uses this to determine if it should store
them. If it does it uses a different magic value so longjmp is able to know
if it should load them.

Remove part of the NetBSD longjmp code that was not ready to be merged.

Start to merge the updated ARM NetBSD setjump/longjmp functions. To begin
with merge the functions but leave out the code to save/load the VFP
registers as that requires other changes to ensure the VFP is enabled
first.

This removes storing the old fpa registers. These were never fully
supported, and the only user of this code I can find have moved to newer
CPUs which use a VFP.

Use GCC's __SOFTFP__ to test whether we're being compiled
with softfloat or not. Now -msoft-float can be overridden
more easily.

Use the RET macro.
For setjmp() and longjmp(), put the signal mask where it's supposed to be,
instead of in the space reserved for fp regs.

Don't define SOFTFLOAT directly in source files, it's now done in the Makefile.

Make setjmp()/longjmp() use sigprocmask.

Import the FreeBSD/arm libc bits.

Obtained from: NetBSD