msp430-asm: use macro_rules! instead of nightly macro syntax.

It may be nice, but y'know what's nicer? Building on stable.

msp430-asm/src/lib.rs

@@ -1,5 +1,4 @@
 //! Helper library for msp430-asm
-#![feature(decl_macro)]
 pub mod split_twice {
     /// Slices a collection into a beginning, middle, and end, based on two unordered indices
     pub trait SplitTwice<'t> {
@@ -63,30 +62,51 @@ pub mod cursor {
     use std::fmt::{Arguments, Display};
 
     /// Moves to the {line}th previous line
-    pub macro previous($line:literal) {
-        csi!("{}F", $line)
+    #[macro_export]
+    macro_rules! previous {
+        ($line:literal) => {
+            csi!("{}F", $line)
+        };
     }
 
     /// Injects a Command Sequence Introducer
-    pub macro csi($($t:tt)*) {
-        format_args!("\x1b[{}", format_args!($($t)*))
+    #[macro_export]
+    macro_rules! csi {
+            ($($t:tt)*) => {
+            format_args!("\x1b[{}", format_args!($($t)*))
+        };
     }
 
     /// Formats the args with a foreground [Color]
-    pub macro fg($fg:expr, $($t:tt)*) {
-        Colorized::new(Some($fg), None, format_args!($($t)*))
+    #[macro_export]
+    macro_rules! fg {
+        ($fg:expr, $($t:tt)*) => {
+            Colorized::new(Some($fg), None, format_args!($($t)*))
+        };
     }
 
     /// Formats the args with a background [Color]
-    pub macro bg($bg:expr, $(t:tt)*) {
-        Colorized::new(None, Some($bg), format_args!($($t)*))
+    #[macro_export]
+    macro_rules! bg {
+        ($bg:expr, $(t:tt)*) => {
+            Colorized::new(None, Some($bg), format_args!($($t)*))
+        };
     }
 
     /// Formats the args with both a foreground and background [Color]
-    pub macro color($fg:expr, $bg:expr, $($t:tt)*) {
-        Colorized::new(Some($fg), Some($bg), format_args!($($t)*))
+    #[macro_export]
+    macro_rules! color {
+        ($fg:expr, $bg:expr, $($t:tt)*) => {
+            Colorized::new(Some($fg), Some($bg), format_args!($($t)*))
+        }
     }
 
+    pub use bg;
+    pub use color;
+    pub use csi;
+    pub use fg;
+    pub use previous;
+
     #[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
     pub enum Color {
         #[default]