run precheckins separately in automerge

The Clang static code analyzer ignores the precheckin return value when using
--status-bugs. Running it twice shouldn't be too slow because we use ccache.
ivs: workaround clang-analyzer warnings

optarg won't be NULL because these options were configured as
`required_argument`. Add assertions to inform Clang about this.
update bigcode

* submodules/bigcode 8406952...2e68469 (3):
  > Merge into master from pull request #32: PPE: workaround clang-analyzer warnings (https://github.com/floodlight/bigcode/pull/32)
  > Merge into master from pull request #31: PPE: add unused attribute to a few functions (https://github.com/floodlight/bigcode/pull/31)
  > Merge into master from pull request #30: bighash: fix pedantic warnings (https://github.com/floodlight/bigcode/pull/30)
update indigo

* submodules/indigo 11397e4...1252d04 (4):
  > Merge into master from pull request #135: fix clang-analyzer warnings (https://github.com/floodlight/indigo/pull/135)
  > Merge into master from pull request #134: OFStateManager: populate table_id in bsn_table_checksum_stats_entry (https://github.com/floodlight/indigo/pull/134)
  > Merge into master from pull request #132: Add more port counters. (https://github.com/floodlight/indigo/pull/132)
  > Merge into master from pull request #133: fix warnings from Clang 3.4 (https://github.com/floodlight/indigo/pull/133)
update infra

* submodules/infra 9405ea9...3913825 (1):
  > Merge into master from pull request #25: AIM: add wrappers for __attribute__ (https://github.com/floodlight/infra/pull/25)
update loxigen-artifacts

* submodules/loxigen-artifacts fd530ef...8e16135 (1):
  > Artifacts from https://github.com/floodlight/loxigen/compare/415d879292453a18b6080c75da2e2975b4513d2e...4087b17e3477cbc9d010d8f78f80cbff0b083882
update infra

* submodules/infra 3913825...5e6c157 (1):
  > Merge into master from pull request #26: AIM: squelch unused variable warnings from ASSERT (https://github.com/floodlight/infra/pull/26)
update loxigen-artifacts

* submodules/loxigen-artifacts 8e16135...528d95f (1):
  > Artifacts from https://github.com/floodlight/loxigen/compare/4087b17e3477cbc9d010d8f78f80cbff0b083882...58a783110072c8a8cbc0d580d8f8dffcb71e8bfa
update indigo

* submodules/indigo 1252d04...1265258 (1):
  > Merge into master from pull request #136: OFStateManager: fix undeclared variable in assertion (https://github.com/floodlight/indigo/pull/136)
Merge into master from pull request #163:
fix clang-analyzer warnings (https://github.com/floodlight/ivs/pull/163)