compiler: Move and modernize

compiler is blitzcc, what I previously called compiler is now compiler_lib

compiler/lib/assem.hpp

@@ -0,0 +1,12 @@
+#pragma once
+#include <istream>
+
+#include <linker.hpp>
+
+class Assem {
+	public:
+	std::istream& in;
+	Module*  mod;
+	Assem(std::istream& in, Module* mod) : in(in), mod(mod) {}
+	virtual void assemble() = 0;
+};