Possible 7.1RC1 bug

Here's a fragment of code that works on 7.0.3 but gives a type mismatch
on 7.1:

Under 7.1RC1, func1 fails and func2 builds OK. The error is:

ERROR: return type mismatch in function: declared to return int4,
returns numeric

It appears that sum(int4) returns type numeric. Shouldn't it return
int4?

create table ints (
inte int4
);

create function func1() returns int4 as '
select coalesce(sum(inte),0) from ints;
' language 'sql';

create function func2() returns int4 as '
select coalesce(sum(inte)::int4,0) from ints;
' language 'sql';