JavaByteCode: Replaced AliasDefinition Visitor Code with assertion Error

Should never be called anyway

JavaBytecodeCompiler/src/main/java/org/openzen/zenscript/javabytecode/compiler/definitions/JavaDefinitionVisitor.java

 
 	@Override
 	public byte[] visitAlias(AliasDefinition definition) {
-		//TODO would that work?
-		return JavaModule.classes.get(definition.name);
+		throw new AssertionError("Aliases shouldn't exist here...");
 	}
 
 	@Override