clang: Let release builds use -O3, like on gcc.

clang: Let release builds use -O3, like on gcc.

Now that http://llvm.org/bugs/show_bug.cgi?id=10031 is fixed, this will hopefully
no longer crash clang.

BUG=84815
TEST=none

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=88425

[Nico, 2011-06-08 19:52:41]

Since there are no release clang trybots, I can't test this before checking in
(well, I could do a local build I guess, but there's no big harm in breaking the
perfclang builder for a short while either.)

I will wait a few hours with landing this, so that the perf builder can collect
perf numbers for the new clang version at O2 first.

[Scott Hess - ex-Googler, 2011-06-08 20:09:03]

LGTM.

[commit-bot: I haz the power, 2011-06-08 22:17:26]

Try job failure for 7104062-1 on linux_clang for step "compile" (clobber build).
It's a second try, previously, step "compile" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_clan...

[Mark Mentovai, 2011-06-09 14:29:49]

LGTM-post-facto