[m-rev.] for review: Merge compiler notes

[Julien Fischer]

Hi Paul,

On Wed, 12 Feb 2014, Paul Bone wrote:

> For review by someone who can check that the new paragraph in
> compiler_design.html should be included or not.

The new paragraph, about the MLDS-asm backend (i.e. the GCC backend)
should not be there since I deleted that backend nearly a year ago!

I only glanced at the rest, but I assume the changes are fairly trivial.

Cheers,
Julien.