refactor: move benchmark directory under test and update all references

The benchmark directory is relocated from the project root into the test directory, and all scripts, documentation links, and gitignore paths are updated accordingly. The test runner is also refactored to explicitly walk subdirectories (core, io, language, limit) instead of using a single test root, and a new test/README.md is added to document the test suite structure. Additionally, the constructor test for the Foo class is updated to add a zero-arity constructor and adjust expected output strings.

test/language/implicit_receiver/inherited_methods.wren

@@ -0,0 +1,23 @@
+class Foo {
+  getter {
+    IO.print("getter")
+  }
+
+  setter=(value) {
+    IO.print("setter")
+  }
+
+  method(a) {
+    IO.print("method")
+  }
+}
+
+class Bar is Foo {
+  test {
+    getter            // expect: getter
+    setter = "value"  // expect: setter
+    method("arg")     // expect: method
+  }
+}
+
+(new Bar).test

test/language/implicit_receiver/instance_methods.wren

@@ -0,0 +1,23 @@
+class Foo {
+  getter {
+    IO.print("getter")
+  }
+
+  setter=(value) {
+    IO.print("setter")
+  }
+
+  method(a) {
+    IO.print("method")
+  }
+
+  test {
+    getter            // expect: getter
+    setter = "value"  // expect: setter
+    method("arg")     // expect: method
+  }
+}
+
+(new Foo).test
+
+// TODO: Need to decide how these interact with globals.

test/language/implicit_receiver/locals_shadow_getter.wren

@@ -0,0 +1,17 @@
+class Foo {
+  bar { "getter" }
+
+  test {
+    IO.print(bar) // expect: getter
+
+    {
+      IO.print(bar) // expect: getter
+      var bar = "local"
+      IO.print(bar) // expect: local
+    }
+
+    IO.print(bar) // expect: getter
+  }
+}
+
+(new Foo).test

test/language/implicit_receiver/locals_shadow_setter.wren

@@ -0,0 +1,20 @@
+class Foo {
+  bar=(value) {
+    IO.print("setter")
+    return value
+  }
+
+  test {
+    bar = "value" // expect: setter
+
+    {
+      bar = "value" // expect: setter
+      var bar = "local"
+      bar = "value" // no expectation
+    }
+
+    bar = "value" // expect: setter
+  }
+}
+
+(new Foo).test

test/language/implicit_receiver/nested_class.wren

@@ -0,0 +1,47 @@
+class Outer {
+  getter {
+    IO.print("outer getter")
+  }
+
+  setter=(value) {
+    IO.print("outer setter")
+  }
+
+  method(a) {
+    IO.print("outer method")
+  }
+
+  test {
+    getter            // expect: outer getter
+    setter = "value"  // expect: outer setter
+    method("arg")     // expect: outer method
+
+    class Inner {
+      getter {
+        IO.print("inner getter")
+      }
+
+      setter=(value) {
+        IO.print("inner setter")
+      }
+
+      method(a) {
+        IO.print("inner method")
+      }
+
+      test {
+        getter            // expect: inner getter
+        setter = "value"  // expect: inner setter
+        method("arg")     // expect: inner method
+      }
+    }
+
+    (new Inner).test
+
+    getter            // expect: outer getter
+    setter = "value"  // expect: outer setter
+    method("arg")     // expect: outer method
+  }
+}
+
+(new Outer).test

test/language/implicit_receiver/static_methods.wren

@@ -0,0 +1,21 @@
+class Foo {
+  static getter {
+    IO.print("getter")
+  }
+
+  static setter=(value) {
+    IO.print("setter")
+  }
+
+  static method(a) {
+    IO.print("method")
+  }
+
+  static test {
+    getter            // expect: getter
+    setter = "value"  // expect: setter
+    method("arg")     // expect: method
+  }
+}
+
+Foo.test