refs #22605
Sym choice nodes are now only allowed to pass through semchecking if
contexts ask for them to (with `efAllowSymChoice`). Otherwise they are
resolved or treated as ambiguous. The contexts that can receive
symchoices in this PR are:
* Call operands and addresses and emulations of such, which will subject
them to overload resolution which will resolve them or fail.
* Type conversion operands only for routine symchoices for type
disambiguation syntax (like `(proc (x: int): int)(foo)`), which will
resolve them or fail.
* Proc parameter default values both at the declaration and during
generic instantiation, which undergo type narrowing and so will resolve
them or fail.
This means unless these contexts mess up sym choice nodes should never
leave the semchecking stage. This serves as a blueprint for future
improvements to intermediate symbol resolution.
Some tangential changes are also in this PR:
1. The `AmbiguousEnum` hint is removed, it was always disabled by
default and since #22606 it only started getting emitted after the
symchoice was soundly resolved.
2. Proc setter syntax (`a.b = c` becoming `` `b=`(a, c) ``) used to
fully type check the RHS before passing the transformed call node to
proc overloading. Now it just passes the original node directly so proc
overloading can deal with its typechecking.
fixes#22598, properly fixes#21887 and fixes test case issue number
When an enum field sym choice has to choose a type, check if its name is
ambiguous in the local scope, then check if the first symbol found in
the local scope is the first symbol in the sym choice. If so, choose
that symbol. Otherwise, give an ambiguous identifier error.
The dependence on the local scope implies this will always give
ambiguity errors for unpicked enum symchoices from generics and
templates and macros from other scopes. We can change `not
isAmbiguous(...) and foundSym == first` to `not (isAmbiguous(...) and
foundSym == first)` to make it so they never give ambiguity errors, and
always pick the first symbol in the symchoice. I can do this if this is
preferred, but no code from CI seems affected.
* clean up some test categories
* mention exact slice issue
* magics into system
* move trangechecks into overflow
* move tmemory to system
* try fix CI
* try fix CI
* final CI fix
