cue: move to external builtin packages

This includes a new generator for builtin packages.

Change-Id: Ieab84e16d9136c2ad5d2d8e8cad49c84a6e0b658
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/6885
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
Reviewed-by: CUE cueckoo <cueckoo@gmail.com>
diff --git a/pkg/html/pkg.go b/pkg/html/pkg.go
new file mode 100644
index 0000000..b611b65
--- /dev/null
+++ b/pkg/html/pkg.go
@@ -0,0 +1,41 @@
+// Code generated by go generate. DO NOT EDIT.
+
+//go:generate rm pkg.go
+//go:generate go run ../gen/gen.go
+
+package html
+
+import (
+	"cuelang.org/go/internal/core/adt"
+	"cuelang.org/go/pkg/internal"
+)
+
+func init() {
+	internal.Register("html", pkg)
+}
+
+var _ = adt.TopKind // in case the adt package isn't used
+
+var pkg = &internal.Package{
+	Native: []*internal.Builtin{{
+		Name:   "Escape",
+		Params: []adt.Kind{adt.StringKind},
+		Result: adt.StringKind,
+		Func: func(c *internal.CallCtxt) {
+			s := c.String(0)
+			if c.Do() {
+				c.Ret = Escape(s)
+			}
+		},
+	}, {
+		Name:   "Unescape",
+		Params: []adt.Kind{adt.StringKind},
+		Result: adt.StringKind,
+		Func: func(c *internal.CallCtxt) {
+			s := c.String(0)
+			if c.Do() {
+				c.Ret = Unescape(s)
+			}
+		},
+	}},
+}