mie: ir: replace mie_module ir object with a builtin generic "module" op

the builtin.module op behaves exactly like any other op, and is designed
to be a container for other ops of any type. it can be used as the
top-level container for other ops (other top-level containers can be used
instead).

this also changes the file format. now, an ir file can only contain a
single top-level op. any other ops in the ir must be contained
directly or indirectly by this top-level op.

mie/ir/module.c

@@ -1,28 +0,0 @@
-#include <mie/ir/module.h>
-#include <mie/ir/op.h>
-#include <stdlib.h>
-#include <string.h>
-
-struct mie_module *mie_module_create(void)
-{
-	struct mie_module *out = malloc(sizeof *out);
-	if (!out) {
-		return NULL;
-	}
-
-	memset(out, 0x0, sizeof *out);
-
-	out->m_names = mie_name_map_create(NULL);
-
-	return out;
-}
-
-void mie_module_destroy(struct mie_module *mod)
-{
-	/* TODO */
-}
-
-struct mie_op *mie_module_add_op(struct mie_module *mod)
-{
-	return mie_vector_emplace_back(mod->m_ops);
-}

mie/ir/op.c

@@ -0,0 +1,32 @@
+#include <mie/ir/op.h>
+#include <stdlib.h>
+
+struct mie_op *mie_op_create(void)
+{
+	struct mie_op *out = malloc(sizeof *out);
+	if (!out) {
+		return NULL;
+	}
+
+	mie_op_init(out);
+
+	return out;
+}
+
+void mie_op_destroy(struct mie_op *op)
+{
+	mie_op_cleanup(op);
+	free(op);
+}
+
+void mie_op_init(struct mie_op *op)
+{
+	memset(op, 0x0, sizeof *op);
+
+	mie_attribute_map_init(&op->op_attrib);
+}
+
+void mie_op_cleanup(struct mie_op *op)
+{
+	/* TODO */
+}