[coreboot] Building the toolchain automatically

[Martin Roth]

coreboot already detects whether the toolchain is built, and already
has targets to build the toolchain for each individual architecture.
It would be trivial to connect these together and simply build the
toolchain for the current architecture if it doesn't exist. Is this
something that is desirable to the coreboot community?

Please vote in the poll if you have an opinion about whether the
toolchain should be built automatically:
http://doodle.com/poll/tu65vbvt9snfcn8p

Poll options are:
- coreboot should build the toolchain for the current architecture if
it doesn't exist.
- coreboot should offer to build the toolchain, but let the user
choose not to build it.
- Leave it as it currently is - someone should update the docs.
- Leave it as it currently is - I volunteer to update the docs.
- Rip out the current toolchain make targets - Building the toolchain
belongs elsewhere.

Additionally, since we are about to detect the version of the
toolchain, and can tell the user if the toolchain needs to be updated,
if we automatically build it, should it automatically be rebuilt when
the build detects that the toolchain is out of date?

Arguments for automatically building the toolchain:
- The docs are always out of date, and nobody updates them when they
change options.
- We're frequently answering questions on how to build the toolchain.

Arguments against automatically building the toolchain:
- "It's feature creep.  The build system should just build coreboot."

I'd really like to know how others feel about this.  To me it's a
trivial thing to add and I feel like it would be very helpful to
beginning coreboot users, but it doesn't really matter to me either
way.  I'm reasonably good at rebuilding the toolchain. :)

Martin