Stop submoduling re2 (#8935)
Summary:
- Use release tarball instead of stale submodule
- faster builds
- more consistent with other stuff
- always defines re2 target, conditionally defines bundled_re2 target
- resolve re2 build TODO in fbmysqlclient CMake, which required this split (fooBuild was the old name for bundled_foo targets) by making it depend on re2 (but not bundled_re2)
- clean up fbmysqlclient's cmake to get it up to speed with our current conventions while I'm here
The net effect is that:
- build of re2 should be faster, as we'll be fetching a source tarball instead of gitsubmodule - and in FB infra, it's cached locally
- we won't spend time fetching re2 sources at all if the system version is new enough
- fbmysqlclient will also build faster if system re2 does not exist or is too old: previously HHVM and fbmysqlclient would each build their own copy
Pull Request resolved: https://github.com/facebook/hhvm/pull/8935
Test Plan: *castle and built on AWS worker.
Reviewed By: shayne-fletcher
Differential Revision:
D32537910
fbshipit-source-id:
6bcbc9eb7e69131dfe68528faddbf6eb65b470aa