goose: skip function body type-checking

Learn this one weird trick to make goose an order of magnitude faster!

Reviewed-by: Herbie Ong <herbie@google.com>
Reviewed-by: Tuo Shan <shantuo@google.com>

internal/goose/goose.go

@@ -28,6 +28,7 @@ func Generate(bctx *build.Context, wd string, pkg string) ([]byte, error) {
 		Build:               new(build.Context),
 		ParserMode:          parser.ParseComments,
 		Cwd:                 wd,
+		TypeCheckFuncBodies: func(string) bool { return false },
 	}
 	*conf.Build = *bctx
 	n := len(conf.Build.BuildTags)