The go/format.Node function fails silently on malformed ASTs, even
though it writes out an invalid tree containing the strings "BadExpr"
and "BadStmt". We fix this by checking for *ast.Bad{Expr,Decl,Stmt}
before running the function. Ultimately, this should be fixed upstream
and just return an error from format.Node.
Change-Id: I2ba25551f0e97c0321d8e757de67360af44044d7
Reviewed-on: https://go-review.googlesource.com/c/149613
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
