While we support initializing records via coercion from an expression
list, e.g.,
local x: X = [$x1=1, $x2=2];
this can sometimes obscure the code to readers, e.g., when assigning to
value declared and typed elsewhere. The language runtime has a similar
overhead since instead of just constructing a known type it needs to
check at runtime that the coercion from the expression list is valid;
this can be slower than just writing the readible code in the first
place, see #4559.
With this patch we use explicit construction, e.g.,
local x = X($x1=1, $x2=2);
If the script layer is able to access the current node's config via
Supervisor::node(), it can handle populating Cluster::nodes. That code
is much more straightforward than an equivalent in-core implementation
(especially with the upcoming change to the cluster table's implementation).
This introduces base/frameworks/cluster/supervisor.zeek and
Cluster::Supervisor::__init_cluster_nodes() for that purpose.
The @load of the Supervisor API in cluster/main.zeek isn't technically
necessary since we already load it explicitly even in init-bare.zeek,
but being explicit seems better.
