[vta] don't crash dumping sched deps

[Alexandre Oliva]

I've only ever run into NULL dep lists while dumping sched info.  I
suppose this may have to do with boundary debug insns that we attempt to
dump anyway or some such, but I haven't spent much time investigating
this.  Checking for NULL doesn't sound like a bad idea in general.

I'm installing this in the VTA branch.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: vta-sched-deps-dump-crash-deps-back.patch
Type: text/x-patch
Size: 1975 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20090301/0ede005e/attachment.bin>
-------------- next part --------------

-- 
Alexandre Oliva           http://www.lsd.ic.unicamp.br/~oliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist      Red Hat Brazil Compiler Engineer