code review 131450043: runtime: give nosplit functions 32 more bytes of headroom

runtime: give nosplit functions 32 more bytes of headroom

The Go calling convention uses more stack space than C.
On 64-bit systems we've been right up against the limit
(128 bytes, so only 16 words) and doing awful things to
our source code to work around it. Instead of continuing
to do awful things, raise the limit to 160 bytes.
I am prepared to raise the limit to 192 bytes if necessary,
but I think this will be enough.

Should fix current link-time stack overflow errors on
        - nacl/arm
        - netbsd/amd64
        - openbsd/amd64
        - solaris/amd64
        - windows/amd64

[rsc, 2014-08-27 18:08:22]

Hello r (cc: golang-codereviews@googlegroups.com, iant),

I'd like you to review this change to
https://code.google.com/p/go/

[rsc, 2014-08-27 18:08:29]

*** Submitted as https://code.google.com/p/go/source/detail?r=07a722aece2d ***

runtime: give nosplit functions 32 more bytes of headroom

The Go calling convention uses more stack space than C.
On 64-bit systems we've been right up against the limit
(128 bytes, so only 16 words) and doing awful things to
our source code to work around it. Instead of continuing
to do awful things, raise the limit to 160 bytes.
I am prepared to raise the limit to 192 bytes if necessary,
but I think this will be enough.

Should fix current link-time stack overflow errors on
        - nacl/arm
        - netbsd/amd64
        - openbsd/amd64
        - solaris/amd64
        - windows/amd64

TBR=r
CC=golang-codereviews, iant
https://codereview.appspot.com/131450043

[gobot, 2014-08-27 18:34:51]

This CL appears to have broken the linux-386-387 builder.
See http://build.golang.org/log/db979e051ce731ae682e76cb4225f8f8107f3b71

[r, 2014-08-27 18:42:56]

LGTM

[aram, 2014-08-27 19:04:20]

LGTM