Adjust to upcoming Base Vararg change

Author: Keno

src/optimize.jl

@@ -243,7 +243,7 @@ function parametric_type_to_expr(t::Type)
     t isa Core.TypeofBottom && return t
     t isa UnionAll && (t = t.body)
     t = t::DataType
-    if t <: Vararg
+    if Base.isvarargtype(t)
         return Expr(:(...), t.parameters[1])
     end
     if t.hasfreetypevars

src/utils.jl

@@ -248,12 +248,16 @@ end
 is_leaf(frame::Frame) = frame.callee === nothing
 
 function is_vararg_type(x)
-    if isa(x, Type)
-        (x <: Vararg && !(x <: Union{})) && return true
-        if isa(x, UnionAll)
-            x = Base.unwrap_unionall(x)
+    if isa(Vararg, Type)
+        if isa(x, Type)
+            (x <: Vararg && !(x <: Union{})) && return true
+            if isa(x, UnionAll)
+                x = Base.unwrap_unionall(x)
+            end
+            return isa(x, DataType) && nameof(x) == :Vararg
         end
-        return isa(x, DataType) && nameof(x) == :Vararg
+    else
+        return isa(x, typeof(Vararg))
     end
     return false
 end