Reproducible BUILD_PATH_PREFIX_MAP

Make builds reproducible by honoring BUILD_PATH_PREFIX_MAP
Upstream has rejected the patch in this form and promised to implement an
alternative they are happy with instead. That hasn't happened yet though.

Bug: https://github.com/golang/go/issues/22491, https://github.com/golang/go/issues/16860
Forwarded: https://golang.org/cl/73291 (rejected upstream though)

Gbp-Pq: Name 0001-Reproducible-BUILD_PATH_PREFIX_MAP.patch

golang-1.11 (1.11.5-1) unstable; urgency=high

  * New upstream version 1.11.5, fixing CVE-2019-6486

[dgit import unpatched golang-1.11 1.11.5-1]

Import golang-1.11_1.11.5.orig.tar.gz

[dgit import orig golang-1.11_1.11.5.orig.tar.gz]

Import golang-1.11_1.11.5-1.debian.tar.xz

[dgit import tarball golang-1.11 1.11.5-1 golang-1.11_1.11.5-1.debian.tar.xz]