[avr] Patch for -mint8 option -- unreviewed patch

[Jim Wilson]

Using 32-bit long long with an 8-bit target is sensible, and is already
done for some other 8-bit targets.  So the concept is OK.

You are defining __AVR_INT8__ in two places, which seems redundant.  You
only need it in one place.  The correct place would be the first one in
TARGET_CPU_CPP_BUILTINS.

The ChangeLog entry isn't correct.  You need to list every macro
modified, and briefly describe the change.  You haven't done this.  So
it should look something like this
* config/avr/avr.h (TARGET_CPU_CPP_BUILTINS): Define __AVR_INT8__
(LONG_LONG_TYPE_SIZE): Check INT_TYPE_SIZE.

The patch is OK with these changes.

The avr has two listed maintainers, so I included them in the cc's in
case they want to comment.

I was going to suggest that a doc change was missing, but then I noticed
that the -mint8 option isn't documented.  Perhaps you could add the
missing documentation?

Jim