code review 7395050: cmd/6g, cmd/8g: switch to DX for indirect call block

cmd/6g, cmd/8g: switch to DX for indirect call block
runtime: add context argument to gogocall

Too many other things use AX, and at least one
(stack zeroing) cannot be moved onto a different
register. Use the less special DX instead.

Preparation for step 2 of http://golang.org/s/go11func.
Nothing interesting here, just split out so that we can
see it's correct before moving on.

[rsc, 2013-02-22 15:47:52]

Hello ken2 (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg/

[rsc, 2013-02-22 15:47:59]

*** Submitted as https://code.google.com/p/go/source/detail?r=237f213fc927 ***

cmd/6g, cmd/8g: switch to DX for indirect call block
runtime: add context argument to gogocall

Too many other things use AX, and at least one
(stack zeroing) cannot be moved onto a different
register. Use the less special DX instead.

Preparation for step 2 of http://golang.org/s/go11func.
Nothing interesting here, just split out so that we can
see it's correct before moving on.

R=ken2
CC=golang-dev
https://codereview.appspot.com/7395050

[ken3, 2013-02-22 17:36:15]

lgtm