Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

MFC r270882, r270930:

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.

Do not generate unwind info in asm functions if _STANDALONE is defined.
The .fnend op causes the assembler to emit RELOC references to unwind
support functions that don't exist in libstand.

Approved by: re(gjb)

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

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.

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.

Let libstand(3) build on ARM.

This is a pre-requisite for loader(8) + U-Boot support library on this arch.

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.

Import the FreeBSD/arm libc bits.

Obtained from: NetBSD