[ccache] Bail out on -arch?

[Bernhard Bauer]

Hi Joel,

I'm currently trying to get ccache to work under Mac OS X for the
Chromium build. In ccache 3.0pre1, there is a change to bail out early
on the -arch flag, which is used by xcodebuild (the standard OS X
build tool), because it's "too hard". What do you mean by that? Is
there a way to accept the flag if I know that I'm always compiling
with the same -arch option (i.e. i386)? So far I have been using
ccache with -arch without any problems.

Thanks,
Bernhard.