Fix VM memory allocation optimizations by reducing what we allocate on the heap

internal/compiler/compiler.go

@@ -173,7 +173,7 @@ func (c *Compiler) Compile(node ast.Node) error {
 		}
 
 	case *ast.IntegerLiteral:
-		integer := &object.Integer{Value: node.Value}
+		integer := object.Integer{Value: node.Value}
 		c.emit(code.OpConstant, c.addConstant(integer))
 
 	case *ast.Null:
@@ -356,7 +356,7 @@ func (c *Compiler) Compile(node ast.Node) error {
 		c.loadSymbol(symbol)
 
 	case *ast.StringLiteral:
-		str := &object.String{Value: node.Value}
+		str := object.String{Value: node.Value}
 		c.emit(code.OpConstant, c.addConstant(str))
 
 	case *ast.ArrayLiteral: