Today it's only recorded for C, but the Go version of the linker will need it.

Change-Id: I0de56d98e8f3f1b7feb830458c0934af367fd29a
Reviewed-on: https://go-review.googlesource.com/6333Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>