Simplified code

src/build/register/UseRegister.go

@@ -0,0 +1,8 @@
+package register
+
+import "git.akyoto.dev/cli/q/src/build/cpu"
+
+// Use marks a register to be currently in use.
+func (f *Machine) UseRegister(register cpu.Register) {
+	f.CurrentScope().Use(register)
+}