- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

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

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

Add the required __aeabi_* functions to libc.

The floating point functions are here rather than compiler-rt because the
libc softfloat code allows us to set the rounding mode.

Use the compiler-rt version __{u,}divsi3 and __{u,}modsi3 on ARM EABI

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

Add each directory's symbol map file to SYM_MAPS.

Use the correct values for softfloat, in both the little endian and the big
endian cases.

Eliminate gdtoa.mk and move its contents to ${MACHINE_ARCH}/Makefile.inc.
The purpose of having a separate file involved an abandoned scheme that
would have kept contrib/gdtoa out of the include path for the rest of libc.

Import a Makefile for arm.