inference: add missing LimitedAccuracy handlings (#42034)

I found we need to handle `LimitedAccuracy` (i.e. collect its
limitations into the current frame and unwrap its type) whenever
we do inter-procedural inference. Especially, we need to handle
it where we use `abstract_call_method` and `abstract_call_method_with_const_args`.
Otherwise we may encounter nested `LimitedAccuracy`, which is really not
expected. So this commit also adds the assertion that checks we never
form nested `LimitedAccuracy`.

I encountered errors due to this when analyzing JET itself by JET,
probably because its codebase makes heavy use of `invoke`.
I couldn't pack them up as simple test cases though.

(cherry picked from commit 6341fa5)

Author: aviatesk

base/compiler/abstractinterpretation.jl

@@ -211,10 +211,7 @@ function abstract_call_gf_by_type(interp::AbstractInterpreter, @nospecialize(f),
         info = ConstCallInfo(info, const_results)
     end
 
-    if rettype isa LimitedAccuracy
-        union!(sv.pclimitations, rettype.causes)
-        rettype = rettype.typ
-    end
+    rettype = collect_limitations!(rettype, sv)
     # if we have argument refinement information, apply that now to get the result
     if is_lattice_bool(rettype) && conditionals !== nothing && fargs !== nothing
         slot = 0
@@ -1177,9 +1174,9 @@ function abstract_invoke(interp::AbstractInterpreter, argtypes::Vector{Any}, sv:
     # end
     const_rt, const_result = abstract_call_method_with_const_args(interp, result, argtype_to_function(ft′), argtypes′, match, sv, false)
     if const_rt !== rt && const_rt ⊑ rt
-        return CallMeta(const_rt, InvokeCallInfo(match, const_result))
+        return CallMeta(collect_limitations!(const_rt, sv), InvokeCallInfo(match, const_result))
     else
-        return CallMeta(rt, InvokeCallInfo(match, nothing))
+        return CallMeta(collect_limitations!(rt, sv), InvokeCallInfo(match, nothing))
     end
 end
 
@@ -1296,7 +1293,7 @@ function abstract_call_opaque_closure(interp::AbstractInterpreter, closure::Part
             info = ConstCallInfo(info, Union{Nothing,InferenceResult}[const_result])
         end
     end
-    return CallMeta(rt, info)
+    return CallMeta(collect_limitations!(rt, sv), info)
 end
 
 function most_general_argtypes(closure::PartialOpaque)

base/compiler/typelattice.jl

@@ -96,8 +96,18 @@ end
 struct LimitedAccuracy
     typ
     causes::IdSet{InferenceState}
-    LimitedAccuracy(@nospecialize(typ), causes::IdSet{InferenceState}) =
-        new(typ, causes)
+    function LimitedAccuracy(@nospecialize(typ), causes::IdSet{InferenceState})
+        @assert !isa(typ, LimitedAccuracy) "malformed LimitedAccuracy"
+        return new(typ, causes)
+    end
+end
+
+@inline function collect_limitations!(@nospecialize(typ), sv::InferenceState)
+    if isa(typ, LimitedAccuracy)
+        union!(sv.pclimitations, typ.causes)
+        return typ.typ
+    end
+    return typ
 end
 
 struct NotFound end