Implemented more arm64 instructions

src/arm/Sub.go

@@ -0,0 +1,9 @@
+package arm
+
+import "git.urbach.dev/cli/q/src/cpu"
+
+// SubRegisterNumber subtracts a number from the given register.
+func SubRegisterNumber(destination cpu.Register, source cpu.Register, number int) uint32 {
+	number &= 0b1111_1111_1111
+	return 0b111100010<<23 | (uint32(number) << 10) | (uint32(source) << 5) | uint32(destination)
+}