Add a code generator for making tests of the examples.

src/examples.rs

@@ -0,0 +1,7 @@
+use codespan_reporting::files::SimpleFiles;
+use crate::backend::Backend;
+use crate::ir::Program as IR;
+use crate::syntax::Program as Syntax;
+use cranelift_jit::JITModule;
+
+include!(concat!(env!("OUT_DIR"), "/examples.rs"));

src/lib.rs

@@ -63,6 +63,8 @@
 //!
 pub mod backend;
 pub mod eval;
+#[cfg(test)]
+mod examples;
 pub mod ir;
 pub mod syntax;