More issues

[Jason Merrill]

More things we should decide on:

How constructors/destructors are run for arrays.  Many compilers use a
__vec_new function; g++ doesn't, to allow for inlining of constructors.

Return values of constructors.  I don't see any reason to return a value
from constructors, since we will always pass in the address of the object.
g++ currently returns that address, for historical reasons (previously, to
support assignment to 'this').

Jason