cmd/go/internal/work: support pkgconf 1.4 and later
Fixes #23373
Fix interfacing with latest(1.4+) pkgconf versions, as they have change the
output format, by extending parsing function splitPkgConfigOutput to accommodate
more possible fragment escaping formats. Function is based on pkgconfigs own
implementation at
https://github.com/pkgconf/pkgconf/blob/master/libpkgconf/argvsplit.c. Along
with this change test case TestSplitPkgConfigOutput have been expanded. Thanks
to ignatenko for help on test cases and insights in to the pkgconfig.
Change-Id: I55301bb564b07128d5564ec1454dd247f84a95c3
Reviewed-on: https://go-review.googlesource.com/86541
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>