Refactor: Restructure project package hierarchy and add initial implementation for assembler instructions, shell commands, and exception handling.

src/jvmMain/kotlin/mtmc/lang/sea/ast/ExpressionSyntaxError.java

@@ -0,0 +1,27 @@
+package mtmc.lang.sea.ast;
+
+import mtmc.lang.ParseException;
+import mtmc.lang.sea.SeaType;
+import mtmc.lang.sea.Token;
+import org.jetbrains.annotations.Nullable;
+
+public final class ExpressionSyntaxError extends Expression implements SyntaxError {
+    @Nullable
+    public final Expression child;
+    public final ParseException exception;
+
+    public ExpressionSyntaxError(Token token, String message) {
+        this(null, token, message);
+    }
+
+    public ExpressionSyntaxError(@Nullable Expression child, Token token, String message) {
+        super(child == null ? token : child.start, token, SeaType.INT);
+        this.child = child;
+        this.exception = new ParseException(new ParseException.Message(token, message));
+    }
+
+    @Override
+    public ParseException exception() {
+        return exception;
+    }
+}