[release-branch.go1.14] time: fix LoadLocationFromTZData with slim tzdata
The extend information of a time zone file with last transition < now
could result in a wrong cached zone because it used the zone of the
last transition.
This could lead to wrong zones in systems with slim zoneinfo.
Fixes #42155
Change-Id: I7c57c35b5cfa58482ac7925b5d86618c52f5444d
Reviewed-on: https://go-review.googlesource.com/c/go/+/264939
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
(cherry picked from commit
70e022e4a83dc996ac4f108e811fbc399ad5565b)
Reviewed-on: https://go-review.googlesource.com/c/go/+/266303
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>