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/if/dangling_else.wren

@@ -0,0 +1,3 @@
+// A dangling else binds to the right-most if.
+if (true) if (false) IO.print("bad") else IO.print("good") // expect: good
+if (false) if (true) IO.print("bad") else IO.print("bad")

test/language/if/else.wren

@@ -0,0 +1,6 @@
+// Evaluate the 'else' expression if the condition is false.
+if (true) IO.print("good") else IO.print("bad") // expect: good
+if (false) IO.print("bad") else IO.print("good") // expect: good
+
+// Allow block body.
+if (false) null else { IO.print("block") } // expect: block

test/language/if/if.wren

@@ -0,0 +1,10 @@
+// Evaluate the 'then' expression if the condition is true.
+if (true) IO.print("good") // expect: good
+if (false) IO.print("bad")
+
+// Allow block body.
+if (true) { IO.print("block") } // expect: block
+
+// Assignment in if condition.
+var a = false
+if (a = true) IO.print(a) // expect: true

test/language/if/newline_after_else.wren

@@ -0,0 +1 @@
+if (true) "ok" else // expect error

test/language/if/newline_after_if.wren

@@ -0,0 +1,2 @@
+if // expect error
+(true) IO.print("bad")

test/language/if/truth.wren

@@ -0,0 +1,8 @@
+// False and null are false.
+if (false) IO.print("bad") else IO.print("false") // expect: false
+if (null) IO.print("bad") else IO.print("null") // expect: null
+
+// Everything else is true.
+if (true) IO.print(true) // expect: true
+if (0) IO.print(0) // expect: 0
+if ("") IO.print("empty") // expect: empty