Add builtin type inference for Kernel#Array

Handle Kernel#Array in MAsgnBox#run0 by registering kernel_array_conv
as a builtin handler. Previously, TypeProf had no special handling for
Kernel#Array, causing the argument type to be returned unchanged rather
than always returning an Array type.

The handler correctly mirrors Ruby's Kernel#Array behavior:
- Range[Elem]       -> Array[Elem]  (via to_a)
- Array[Elem]       -> Array[Elem]  (pass through)
- Literal array     -> same type    (pass through)
- Other types (T)   -> Array[T]     (wrap)

Author: sekito1107

lib/typeprof/core/builtin.rb

@@ -247,6 +247,44 @@ def kernel_send(changes, node, ty, a_args, ret)
       true
     end
 
+    def kernel_array(changes, node, ty, a_args, ret)
+      return false unless a_args.positionals.size == 1
+
+      arg_vtx = a_args.positionals[0]
+      elem_vtx = Vertex.new(node)
+      handled = false
+      needs_elem_wrap = false
+
+      arg_vtx.each_type do |arg_ty|
+        handled = true
+        case arg_ty
+        when Type::Instance
+          if arg_ty.mod == @genv.mod_range && arg_ty.args && !arg_ty.args.empty?
+            changes.add_edge(@genv, arg_ty.args[0], elem_vtx)
+            needs_elem_wrap = true
+          elsif arg_ty.mod == @genv.mod_ary
+            changes.add_edge(@genv, Source.new(arg_ty), ret)
+          else
+            changes.add_edge(@genv, Source.new(arg_ty), elem_vtx)
+            needs_elem_wrap = true
+          end
+        when Type::Array
+          changes.add_edge(@genv, Source.new(arg_ty), ret)
+        else
+          changes.add_edge(@genv, Source.new(arg_ty), elem_vtx)
+          needs_elem_wrap = true
+        end
+      end
+
+      return false unless handled
+
+      if needs_elem_wrap
+        ary_ty = @genv.gen_ary_type(elem_vtx)
+        changes.add_edge(@genv, Source.new(ary_ty), ret)
+      end
+      true
+    end
+
     def deploy
       [
         [method(:class_new), [:Class], false, :new],
@@ -262,6 +300,7 @@ def deploy
         [method(:kernel_send), [:BasicObject], false, :__send__],
         [method(:kernel_send), [:Kernel], false, :public_send],
         [method(:kernel_send), [:Kernel], false, :send],
+        [method(:kernel_array), [:Kernel], false, :Array],
       ].each do |builtin, cpath, singleton, mid|
         me = @genv.resolve_method(cpath, singleton, mid)
         me.builtin = builtin

scenario/misc/kernel_array.rb

@@ -0,0 +1,19 @@
+## update
+def from_range
+  Array(1..5)
+end
+
+def from_literal_array
+  Array([1, 2, 3])
+end
+
+def from_integer
+  Array(42)
+end
+
+## assert
+class Object
+  def from_range: -> Array[Integer]
+  def from_literal_array: -> [Integer, Integer, Integer]
+  def from_integer: -> Array[Integer]
+end