cmd/compile: eliminate use of Trecur in formatting routines
CL 38147 eliminated package gc globals in formatting routines.
However, tconv still used the Type field Trecur
to avoid infinite recursion when formatting recursive
interfaces types such as (test/fixedbugs398.go):
type i1 interface {
F() interface {
i1
}
}
type i2 interface {
F() interface {
i2
}
}
This CL changes the recursion prevention to use a parameter,
and threads it through the formatting routines.
Because this fundamentally limits the embedding depth
of all types, it sets the depth limit to be much higher.
In practice, it is unlikely to impact any code at all,
one way or the other.
The remaining uses of Type.Trecur are boolean in nature.
A future CL will change Type.Trecur to be a boolean flag.
The removal of a couple of mode.Sprintf calls
makes this a very minor net performance improvement: