[] and struct in interfaces.
other [] cleanup.

convert() is gone.

R=r
DELTA=352  (144 added, 68 deleted, 140 changed)
OCL=21660
CL=21662
diff --git a/src/runtime/runtime.h b/src/runtime/runtime.h
index c0f943a..bb970da 100644
--- a/src/runtime/runtime.h
+++ b/src/runtime/runtime.h
@@ -48,8 +48,10 @@
 typedef	struct	Stktop		Stktop;
 typedef	struct	String		*string;
 typedef	struct	Usema		Usema;
-typedef	struct	SigTab	SigTab;
-typedef	struct	MCache	MCache;
+typedef	struct	SigTab		SigTab;
+typedef	struct	MCache		MCache;
+typedef	struct	Iface		Iface;
+typedef	struct	Itype		Itype;
 
 /*
  * per cpu declaration
@@ -105,6 +107,11 @@
 	int32	len;
 	byte	str[1];
 };
+struct Iface
+{
+	Itype *type;
+	void *data[1];	// could make bigger later
+};
 
 struct	Array
 {				// must not move anything