- 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

Regression tests for bugs in gdtoa.

Regression test for a recently fixed strtod bug.

Remove some test instrumentation. (The Symbol.map changes broke it anyway.)

Tests for rounding, and for the leading 0's bug.

Remove the test that ensures that when the string "nan(...)" is converted
to floating-point, the result is a quiet NaN. The current implementation
may return a signaling NaN, and the vendor has no plans for changing this,
for reasons explained in the comment I added.

Fix cut-and-paste bugs in the regression tests.

- Split tests into three rough categories.
- Use fesetround() instead of fpsetround(), and add tests for
various rounding modes.
- Test that all NaNs generated are quiet.

Some of these tests won't pass until problems in vendor sources
(gdtoa and gcc) are fixed and new versions imported, but I
want to get these changes into the tree before I accidentally
blow them away again. :-(

Switch over to a different, more flexible test output protocol that's
understood by Perl's Test::Harness module and prove(1) commands.

Update README to describe the new protocol. The work's broken down into
two main sets of changes.

First, update the existing test programs (shell scripts and C programs)
to produce output in the ok/not ok format, and to, where possible, also
produce a header describing the number of tests that are expected to be
run.

Second, provide the .t files that actually run the tests. In some cases
these are copies of, or very similar too, scripts that already existed.
I've kept the old scripts around so that it's possible to verify that
behaviour under this new system (in terms of whether or not a test fails)
is identical to the behaviour under the old system.

Add a TODO file.

Add regression tests for some of the bugs recently discovered in the
vendor's strtod() implementation.

While here, disable some of the long double tests on i386, since
FreeBSD/i386 is the only port that doesn't evaluate long doubles in
their full precision (due to constant folding bugs in gcc).

Work around a recently-introduced gcc bug. The compiler no longer
accepts certain floating point constant representations that are
legal in C99.

Add regression tests for floating point parsing in scanf(3).