tree a77991ffd27f0283edecc9307ff8e51536a1fd6a
parent deeeb31f8ba0f196fbc9ca2a177d59d57ea50b32
author Dmitry Shevchenko <dmishe@google.com> 1475543776 +0000
committer Damien Martin-Guillerez <dmarting@google.com> 1475571398 +0000

Rollback of commit deeeb31f8ba0f196fbc9ca2a177d59d57ea50b32.

*** Reason for rollback ***

Breaks builds with current blaze

*** Original change description ***

Add a way to select non-default Xcode toolchain

* Adds a flag --xcode_toolchain which sets TOOLCHAINS env variable for xcrun.
* Updates swift_library to work with this flag when selecting Swift runtime location.
* By default the flag has a null value and is not set in env.

--
MOS_MIGRATED_REVID=135053864