golang: Use new -trimpath option when compiling Go packages

golang: Use new -trimpath option when compiling Go packages

Go 1.13 added a new -trimpath option to the "go build" command[1] that
removes system paths from compiled executables. This replaces the
previous -trimpath flags.

There are still system paths in the compiled executable (for crti.o and
crtn.o, when cross-compiling); these appear to be stripped during the
packaging process.

[1]: https://golang.org/doc/go1.13#trimpath

Signed-off-by: Jeffery To <jeffery.to@gmail.com>
(cherry-picked from commit 22ee6e86a08d1e59608c50495d25e49378174e5a)