code review 6822048: cmd/gc: racewalk: fix a bunch of minor issues

cmd/gc: racewalk: fix a bunch of minor issues
1. Prepend racefuncenter() to fn->enter -- fn->enter can contain new() calls,
and we want them to be in the scope of the function.
2. Dump fn->enter and fn->exit.
3. Add TODO that OTYPESW expression can contain interesting memory accesses.
4. Ignore only _ names instead of all names starting with _.

[dvyukov, 2012-10-29 19:02:28]

Hello golang-dev@googlegroups.com,

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

[rsc, 2012-11-01 16:59:00]

LGTM

[dvyukov, 2012-11-01 18:56:21]

*** Submitted as http://code.google.com/p/go/source/detail?r=e9002d732849 ***

cmd/gc: racewalk: fix a bunch of minor issues
1. Prepend racefuncenter() to fn->enter -- fn->enter can contain new() calls,
and we want them to be in the scope of the function.
2. Dump fn->enter and fn->exit.
3. Add TODO that OTYPESW expression can contain interesting memory accesses.
4. Ignore only _ names instead of all names starting with _.

R=golang-dev, rsc
CC=golang-dev
http://codereview.appspot.com/6822048