[GLib] Support build append in builder

[asfimport]

It improves performance.

Reporter: Kouhei Sutou / @kou
Assignee: Kouhei Sutou / @kou

PRs and other links:

• GitHub Pull Request #1110

_{Note: This issue was originally created as ARROW-1548. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
Issue resolved by pull request 1110
#1110