Two small infrastructure extensions for passing information into the

logging framework.

- To enable passing a type into a bif, there's now a new
  BroType-derived class TypeType and a corresponding TYPE_TYPE tag.
  With that, a Val can now have a type as its value.

  This is experimental for now.

- RecordVal's get a new method CoerceTo() to coerce their value into a
  another record type with the usual semantics. Most of the code in
  there was previously in RecordContructorExpr::InitVal(), which is
  now calling the new CoerceTo() method.

src/Type.h

@@ -31,6 +31,7 @@ typedef enum {
 	TYPE_FUNC,
 	TYPE_FILE,
 	TYPE_VECTOR,
+	TYPE_TYPE,
 	TYPE_ERROR
 #define NUM_TYPES (int(TYPE_ERROR) + 1)
 } TypeTag;
@@ -59,6 +60,7 @@ class ListExpr;
 class EnumType;
 class Serializer;
 class VectorType;
+class TypeType;
 
 const int DOES_NOT_MATCH_INDEX = 0;
 const int MATCHES_INDEX_SCALAR = 1;
@@ -151,6 +153,7 @@ public:
 		CHECK_TYPE_TAG(TYPE_SUBNET, "BroType::AsSubNetType");
 		return (const SubNetType*) this;
 		}
+
 	SubNetType* AsSubNetType()
 		{
 		CHECK_TYPE_TAG(TYPE_SUBNET, "BroType::AsSubNetType");
@@ -192,6 +195,18 @@ public:
 		return (VectorType*) this;
 		}
 
+	const TypeType* AsTypeType() const
+	        {
+		CHECK_TYPE_TAG(TYPE_TYPE, "BroType::AsTypeType");
+		return (TypeType*) this;
+		}
+
+	TypeType* AsTypeType()
+	        {
+		CHECK_TYPE_TAG(TYPE_TYPE, "BroType::AsTypeType");
+		return (TypeType*) this;
+		}
+
 	int IsSet() const
 		{
 		return tag == TYPE_TABLE && (YieldType() == 0);
@@ -359,6 +374,19 @@ protected:
 	ID* return_value;
 };
 
+class TypeType : public BroType {
+public:
+	TypeType(BroType* t) : BroType(TYPE_TYPE)	{ type = t->Ref(); }
+	~TypeType()	{ Unref(type); }
+
+	BroType* Type()	{ return type; }
+
+protected:
+	TypeType()	{}
+
+	BroType* type;
+};
+
 class TypeDecl {
 public:
 	TypeDecl(BroType* t, const char* i, attr_list* attrs = 0);