Ion ternaries with string literals on one side

[tjpalmer]

This doesn't work at present:

token.pos.name = name ? name : "<string>";

It gives the following error:

error: Left and right operands of ternary expression must have arithmetic types or identical types

Instead, I have to cast:

token.pos.name = name ? name : (:char const*)"<string>";

It would be nice if the compiler could auto-coerce string literals to char const*.

There might be other cases where this applies, too, beyond ternaries. It's just the case where I remember I've run across it.