compiling Chromium 28 with clang33 fixes "unclickable" links

[Brad Karp]

Given hope by Tony's experience, I tried building Chromium 28 on my
9.1-RELEASE amd64 box with clang33 instead of the default 9.1R clang (3.1).

Success here, too: building with clang33 fixes the "unclickable" links
problem I and others had when building with 9.1R's default clang.

Perhaps the port maintainer might consider requiring clang33 for those
who build with clang on 9.1R and earlier for the time being?

-Brad, bkarp at cs.ucl.ac.uk