Revert restrictict exp.@var to types in the same hierarchy

spec/compiler/codegen/c_struct_spec.cr

@@ -288,14 +288,8 @@ describe "Code gen: struct" do
         end
       end
 
-      struct LibFoo::Foo
-        def _x
-          @x
-        end
-      end
-
       f = LibFoo::Foo.new x: 123
-      f._x
+      f.@x
       )).to_i.should eq(123)
   end
 

spec/compiler/codegen/class_spec.cr

@@ -293,14 +293,10 @@ describe "Code gen: class" do
       class Foo
         def initialize(@x : Int32)
         end
-
-        def self.read(foo)
-          foo.@x
-        end
       end
 
       foo = Foo.new(1)
-      Foo.read(foo)
+      foo.@x
       )).to_i.should eq(1)
   end
 
@@ -309,17 +305,13 @@ describe "Code gen: class" do
       class Foo
         def initialize(@x : Int32)
         end
-
-        def self.read(foo)
-          foo.@x
-        end
       end
 
       class Bar < Foo
       end
 
       foo = Foo.new(1) || Bar.new(2)
-      Foo.read(foo)
+      foo.@x
       )).to_i.should eq(1)
   end
 

spec/compiler/codegen/macro_spec.cr

@@ -1459,13 +1459,9 @@ describe "Code gen: macro" do
         {% begin %}
           @x = 1
         {% end %}
-
-        def _x
-          @x
-        end
       end
 
-      Foo.new._x
+      Foo.new.@x
       ), inject_primitives: false).to_i.should eq(1)
   end
 

spec/compiler/codegen/pointer_spec.cr

@@ -356,14 +356,10 @@ describe "Code gen: pointer" do
         def x
           @x
         end
-
-        def self.ptr(foo)
-          pointerof(foo.@x)
-        end
       end
 
       foo = Foo.new
-      Foo.ptr(foo).value = 123
+      pointerof(foo.@x).value = 123
       foo.x
       )).to_i.should eq(123)
   end

spec/compiler/codegen/proc_spec.cr

@@ -727,13 +727,9 @@ describe "Code gen: proc" do
         def self.foo
           42
         end
-
-        def _f
-          @f
-        end
       end
 
-      Foo.new._f.call
+      Foo.new.@f.call
       )).to_i.should eq(42)
   end
 

spec/compiler/codegen/struct_spec.cr

@@ -414,10 +414,6 @@ describe "Code gen: struct" do
         def initialize
           @x = 21
         end
-
-        def self.access(foo)
-          foo.@x
-        end
       end
 
       struct Bar < Foo
@@ -429,7 +425,7 @@ describe "Code gen: struct" do
       struct Baz < Foo
       end
 
-      Foo.access(Bar.new.as(Foo))
+      Bar.new.as(Foo).@x
       )).to_i.should eq(42)
   end
 

spec/compiler/semantic/c_struct_spec.cr

@@ -303,14 +303,8 @@ describe "Semantic: struct" do
         end
       end
 
-      struct LibFoo::Foo
-        def self.read(foo)
-          foo.@x
-        end
-      end
-
       f = LibFoo::Foo.new x: 123
-      LibFoo::Foo.read(f)
+      f.@x
       )) { int32 }
   end
 

spec/compiler/semantic/class_spec.cr

@@ -481,15 +481,47 @@ describe "Semantic: class" do
     assert_error "Number.allocate", "can't instantiate abstract struct Number"
   end
 
-  it "errors if reading ivar from non-ivar container" do
-    assert_error %(
-      struct Int32
-        def foo
-          1.@y
+  it "reads an object instance var" do
+    assert_type(%(
+      class Foo
+        def initialize(@x : Int32)
+        end
+      end
+
+      foo = Foo.new(1)
+      foo.@x
+      )) { int32 }
+  end
+
+  it "reads a virtual type instance var" do
+    assert_type(%(
+      class Foo
+        def initialize(@x : Int32)
         end
       end
 
-      1.foo
+      class Bar < Foo
+      end
+
+      foo = Foo.new(1) || Bar.new(2)
+      foo.@x
+      )) { int32 }
+  end
+
+  it "errors if reading non-existent ivar" do
+    assert_error %(
+      class Foo
+      end
+
+      foo = Foo.new
+      foo.@y
+      ),
+      "Can't infer the type of instance variable '@y' of Foo"
+  end
+
+  it "errors if reading ivar from non-ivar container" do
+    assert_error %(
+      1.@y
       ),
       "can't use instance variables inside primitive types (at Int32)"
   end
@@ -924,14 +956,10 @@ describe "Semantic: class" do
         def foo
           @foo
         end
-
-        def self.read(foo)
-          foo.@foo
-        end
       end
 
       f = Foo.new
-      Foo.read(f)
+      f.@foo
       ),
       "Can't infer the type of instance variable '@foo' of Foo"
   end

spec/compiler/semantic/instance_var_spec.cr

@@ -888,13 +888,9 @@ describe "Semantic: instance var" do
         def x
           @x ||= 1
         end
-
-        def _x
-          @x
-        end
       end
 
-      Foo.new._x
+      Foo.new.@x
       )) { nilable int32 }
   end
 
@@ -904,13 +900,9 @@ describe "Semantic: instance var" do
         def x
           x = @x ||= 1
         end
-
-        def _x
-          @x
-        end
       end
 
-      Foo.new._x
+      Foo.new.@x
       )) { nilable int32 }
   end
 
@@ -4705,13 +4697,9 @@ describe "Semantic: instance var" do
             @never_nil = 2
           end
         end
-
-        def _never_nil
-          @never_nil
-        end
       end
 
-      Foo.new._never_nil
+      Foo.new.@never_nil
       )) { int32 }
   end
 
@@ -4726,10 +4714,6 @@ describe "Semantic: instance var" do
             @never_nil = 2
           end
         end
-
-        def _never_nil
-          @never_nil
-        end
       end
 
       class Bar
@@ -4740,13 +4724,9 @@ describe "Semantic: instance var" do
             @never_nil = 2
           end
         end
-
-        def _never_nil
-          @never_nil
-        end
       end
 
-      {Foo.new._never_nil, Bar.new._never_nil}
+      {Foo.new.@never_nil, Bar.new.@never_nil}
     )) { tuple_of([int32, int32]) }
   end
 
@@ -4860,13 +4840,9 @@ describe "Semantic: instance var" do
 
       class Foo
         @foo = Gen(Int32 | A).new
-
-        def _foo
-          @foo
-        end
       end
 
-      Foo.new._foo
+      Foo.new.@foo
     )) { generic_class "Gen", union_of(int32, types["A"]) }
   end