feat: replace per-type equality primitives with unified object_eqeq and wrenGetClass

Move equality and inequality primitives from Bool and Function to a single Object-level implementation using valuesEqual, and add wrenGetClass to return the runtime class of any value. Refactor newSingleClass to inherit methods from superclass and wire metaclass superclass to classClass. Add type-checking tests for all built-in types and class inheritance.

test/bool_type.wren

@@ -0,0 +1,4 @@
+io.write(true is Bool)      // expect: true
+io.write(true is Object)    // expect: true
+io.write(true is Num)       // expect: false
+io.write(true.type == Bool) // expect: true

test/class_equality.wren

@@ -0,0 +1,13 @@
+io.write(Num == Num)  // expect: true
+io.write(Num == Bool) // expect: false
+
+// Not equal to other types.
+io.write(Num == 123)  // expect: false
+io.write(Num == true) // expect: false
+
+io.write(Num != Num)  // expect: false
+io.write(Num != Bool) // expect: true
+
+// Not equal to other types.
+io.write(Num != 123)  // expect: true
+io.write(Num != true) // expect: true

test/fn_type.wren

@@ -0,0 +1,4 @@
+io.write((fn 0) is Function)      // expect: true
+io.write((fn 0) is Object)        // expect: true
+io.write((fn 0) is String)        // expect: false
+io.write((fn 0).type == Function) // expect: true

test/is.wren

@@ -1,3 +1,4 @@
+io.write(Num is Class) // expect: true
 io.write(true is Bool) // expect: true
 io.write((fn 1) is Function) // expect: true
 io.write(123 is Num) // expect: true
@@ -11,6 +12,32 @@ io.write((fn 1) is Num) // expect: false
 io.write("s" is Null) // expect: false
 io.write(123 is String) // expect: false
 
+// Everything extends Object.
+io.write(Num is Object) // expect: true
+io.write(null is Object) // expect: true
+io.write(true is Object) // expect: true
+io.write((fn 1) is Object) // expect: true
+io.write("s" is Object) // expect: true
+io.write(123 is Object) // expect: true
+
+// Inheritance.
+class A {}
+class B is A {}
+class C is B {}
+var a = A.new
+var b = B.new
+var c = C.new
+
+io.write(a is A) // expect: true
+io.write(a is B) // expect: false
+io.write(a is C) // expect: false
+io.write(b is A) // expect: true
+io.write(b is B) // expect: true
+io.write(b is C) // expect: false
+io.write(c is A) // expect: true
+io.write(c is B) // expect: true
+io.write(c is C) // expect: true
+
 // TODO(bob): Non-class on RHS.
 // TODO(bob): Precedence and associativity.
 // TODO(bob): Metaclasses ("Num is Class").

test/list_type.wren

@@ -0,0 +1,4 @@
+io.write([] is List)      // expect: true
+io.write([] is Object)    // expect: true
+io.write([] is Bool)      // expect: false
+io.write([].type == List) // expect: true

test/null_type.wren

@@ -0,0 +1,4 @@
+io.write(null is Null)      // expect: true
+io.write(null is Object)    // expect: true
+io.write(null is Bool)      // expect: false
+io.write(null.type == Null) // expect: true

test/num_type.wren

@@ -0,0 +1,4 @@
+io.write(123 is Num)      // expect: true
+io.write(123 is Object)   // expect: true
+io.write(123 is String)   // expect: false
+io.write(123.type == Num) // expect: true

test/string_type.wren

@@ -0,0 +1,4 @@
+io.write("s" is String)      // expect: true
+io.write("s" is Object)      // expect: true
+io.write("s" is Num)         // expect: false
+io.write("s".type == String) // expect: true