I don't have strong understanding of the AST structure, so I'm
not sure if this is the right way to handle function call statements.

Change-Id: Ib526f667ab483b32d9fd17da800b5d6f4b26c4c9
Reviewed-on: https://go-review.googlesource.com/11139Reviewed-by: Keith Randall <khr@golang.org>