rearrange to make reason for if clear.

Fixes #911.

R=agl1
CC=golang-dev
https://golang.org/cl/1774044

R=rsc, brainman
CC=golang-dev
https://golang.org/cl/1773041

Fixes #912.

R=rsc
CC=golang-dev
https://golang.org/cl/1819041

Fixes #900.

R=rsc
CC=golang-dev
https://golang.org/cl/1756042

- sign to determine if a value is < 0, == 0, > 0
- abs to compute absolute value
- Rat.IsInt to test if a rational number is representable as an integer

R=rsc
CC=golang-dev
https://golang.org/cl/1761042

R=rsc
CC=golang-dev
https://golang.org/cl/1815042

(Iter() is almost never the right mechanism to call.
Per discussion with rsc.)

R=rsc
CC=golang-dev
https://golang.org/cl/1771043

remove the print statements.

This change is because of the port of gccgo to RTEMS.
These tests use the GCC DejaGNU framework. In some cases,
the tests need to be run on qemu where the status code
cannot be sent back to DejaGNU, so it prints the exit status
by putting a wrapper around the exit and abort calls.

This testcase closes the stdout, and hence prohibits DejaGNU
from knowing the status in such cases, and causes this test
to be wrongly declared as a failure.

R=rsc, iant
CC=golang-dev
https://golang.org/cl/1792042

Benchmarks 25ns/op (was 58ns/op) on 2.53GHz Intel Core 2 Duo.

R=rsc
CC=golang-dev
https://golang.org/cl/1740043

R=rsc
CC=golang-dev
https://golang.org/cl/1496042

R=rsc
CC=Raj_, golang-dev
https://golang.org/cl/1740044

R=iant
CC=golang-dev
https://golang.org/cl/1805041

R=r
CC=golang-dev
https://golang.org/cl/1762044

R=r
CC=golang-dev
https://golang.org/cl/1791041

R=r
CC=golang-dev
https://golang.org/cl/1790041

(matching latest syntax changes)

R=r
CC=golang-dev
https://golang.org/cl/1762042

* Allow an exponent part. This is necessary for exp/eval.
* Fix a bug for input that had no numbers after the decimal.
* In Int.SetString, allow a leading + sign.
* In Int.SetString, error if the input is "-" with no number.
* In nat.scan, normalize the resulting nat.

R=gri
CC=golang-dev
https://golang.org/cl/1733045

Fixes #899.

R=golang-dev, rminnich, adg
CC=golang-dev
https://golang.org/cl/1749041

R=nigeltao
CC=golang-dev
https://golang.org/cl/1682052

	    updated thread.c to provide destroylock, which seems to be
	      required to link.
        updated README with different virtualization programs.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/1746047

In response to this recurring issue:
	http://groups.google.com/group/golang-nuts/t/710d1e8347cd51fa

R=r
CC=golang-dev
https://golang.org/cl/1682050

        (TBR because this is just addressing previous review comments.)

R=r
CC=golang-dev
https://golang.org/cl/1697048

R=r, adg, rsc
CC=golang-dev
https://golang.org/cl/1684051

Fixes #728.

R=r
CC=golang-dev
https://golang.org/cl/1706053

R=r
CC=golang-dev
https://golang.org/cl/1674045

Fixes #885.

R=ken2
CC=golang-dev
https://golang.org/cl/1680048

R=gri, iant, ken2, r
CC=golang-dev
https://golang.org/cl/1687047

R=r
CC=golang-dev
https://golang.org/cl/1712048

R=rsc
CC=golang-dev
https://golang.org/cl/1734046

R=rsc
CC=golang-dev
https://golang.org/cl/1741047

panic if base is invalid.

R=rsc
CC=golang-dev
https://golang.org/cl/1702050

Use a count of -1 for infinity.  Ditto for Replace.

R=rsc
CC=golang-dev
https://golang.org/cl/1704044

R=ken2
CC=golang-dev
https://golang.org/cl/1693047

libmach: disassemble CMPPD as 6a expects

R=ken2
CC=Charlie Dorian, golang-dev
https://golang.org/cl/1704046

(Here, quoted strings are the official AMD names.)

The amd64 "movsxd" instruction, when invoked
with a 64-bit REX prefix, moves and sign extends
a 32-bit value from register or memory into a
64-bit register.  6.out.h spells this MOVLQSX.

6.out.h also includes MOVLQZX, the zero extending
version, which it implements as "movsxd" without
the REX prefix.  Without the REX prefix it's only sign
extending 32 bits to 32 bits (i.e., not doing anything
to the bits) and then storing in a 32-bit register.
Any write to a 32-bit register zeros the top half of the
corresponding 64-bit register, giving the advertised effect.
This particular implementation of the functionality is
non-standard, because an ordinary 32-bit "mov" would
do the same thing.

Because it is non-standard, it is often mishandled or
not handled by binary translation tools like valgrind.
Switching to the standard "mov" makes the binaries
work better with those tools.

It's probably useful in 6c and 6g to have an explicit
instruction, though, so that the intent of the size
change is clear.  Thus we leave the concept of MOVLQZX
and just implement it by the standard "mov" instead of
the non-standard 32-bit "movsxd".

Fixes #896.

R=ken2
CC=golang-dev
https://golang.org/cl/1733046

R=rsc
CC=golang-dev
https://golang.org/cl/1705041

R=iant
CC=golang-dev
https://golang.org/cl/1666048

R=r
CC=golang-dev
https://golang.org/cl/1650041

With these changes, goinstall is now able to use branches
maintained with Bazaar located in Launchpad.

Project aliases such as /project and /project/series are
supported in addition to specific user or team branches
such as /~user/project/branch.  Temporary branches under
the +junk special project are also supported.

As a curious side effect, since Launchpad is able to import
code from other locations, they can be indirectly
accessible too if desired.

R=rsc
CC=golang-dev
https://golang.org/cl/1699050

R=adg
CC=golang-dev
https://golang.org/cl/1693046