language: rename maketables.go to gen.go

Change-Id: I95f7776127dfa09bffd33e89d8a7b45fbafbb5fa
Reviewed-on: https://go-review.googlesource.com/47345
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Nigel Tao <nigeltao@golang.org>

language/gen.go

diff --git a/language/maketables.go b/language/gen.go
similarity index 100%
rename from language/maketables.go
rename to language/gen.go

language/language.go

diff --git a/language/language.go b/language/language.go
index 5eecceb..a2d0378 100644
--- a/language/language.go
+++ b/language/language.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate go run maketables.go gen_common.go -output tables.go
+//go:generate go run gen.go gen_common.go -output tables.go
 //go:generate go run gen_index.go
 
 // Package language implements BCP 47 language tags and related functionality.