Unified the C# mod and the Rust compiler into a monorepo

rust_compiler/libs/compiler/src/test/function_declaration.rs

@@ -0,0 +1,58 @@
+use indoc::indoc;
+use pretty_assertions::assert_eq;
+
+#[test]
+fn test_function_declaration_with_spillover_params() -> anyhow::Result<()> {
+    let compiled = compile!(debug r#"
+        // we need more than 4 params to 'spill' into a stack var
+        fn doSomething(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) {};
+    "#);
+
+    assert_eq!(
+        compiled,
+        indoc! {"
+            j main
+            doSomething:
+            pop r8 #arg9
+            pop r9 #arg8
+            pop r10 #arg7
+            pop r11 #arg6
+            pop r12 #arg5
+            pop r13 #arg4
+            pop r14 #arg3
+            push ra
+            sub r0 sp 1
+            get ra db r0
+            sub sp sp 3
+            j ra
+        "}
+    );
+
+    Ok(())
+}
+
+#[test]
+fn test_function_declaration_with_register_params() -> anyhow::Result<()> {
+    let compiled = compile!(debug r#"
+        // This is a test function declaration with no body
+        fn doSomething(arg1, arg2) {
+        };
+    "#);
+
+    assert_eq!(
+        compiled,
+        indoc! {"
+            j main
+            doSomething:
+            pop r8 #arg2
+            pop r9 #arg1
+            push ra
+            sub r0 sp 1
+            get ra db r0
+            sub sp sp 1
+            j ra
+        "}
+    );
+
+    Ok(())
+}