Merged: Add uxn target

Add uxn target

examples/countTo10.cal

@@ -1,11 +1,6 @@
 include "cores/select.cal"
 include "std/io.cal"
 
-func new_line begin
-	13 printch
-	10 printch
-end
-
 let cell i
 0 i !
 

examples/sierpinski.cal

@@ -1,5 +1,4 @@
 include "cores/select.cal"
-include "std/io.cal"
 
 func sierpinski begin
 	let cell n

examples/stars.cal

@@ -1,5 +1,4 @@
 include "cores/select.cal"
-include "std/io.cal"
 
 let cell x 0 x !
 let cell y 0 y !

source/app.d

@@ -10,6 +10,7 @@ import callisto.compiler;
 import callisto.language;
 import callisto.optimiser;
 import callisto.preprocessor;
+import callisto.backends.uxn;
 import callisto.backends.y32;
 import callisto.backends.rm86;
 import callisto.backends.linux86;
@@ -39,6 +40,7 @@ Backends:
 	rm86    - Real mode x86 and MS-DOS
 	linux86 - Linux for 64-bit x86
 	y32     - YETI-32
+	uxn     - Varvara/Uxn
 ";
 
 int main(string[] args) {
@@ -147,6 +149,10 @@ int main(string[] args) {
 							backend = new BackendY32();
 							break;
 						}
+						case "uxn": {
+							backend = new BackendUXN();
+							break;
+						}
 						default: {
 							stderr.writefln("Unknown backend '%s'", args[i]);
 							return 1;

source/backends/linux86.d

@@ -166,6 +166,8 @@ class BackendLinux86 : CompilerBackend {
 		return ret ~ format("rm %s.asm %s.o", compiler.outFile, compiler.outFile);
 	}
 
+	override long MaxInt() => -1;
+
 	override void BeginMain() {
 		output ~= "__calmain:\n";
 	}

source/backends/rm86.d

@@ -140,6 +140,8 @@ class BackendRM86 : CompilerBackend {
 		format("rm %s.asm", compiler.outFile)
 	];
 
+	override long MaxInt() => 0xFFFF;
+
 	override void BeginMain() {
 		output ~= "__calmain:\n";
 	}