[clangd] Don't rebuild background index until we indexed one TU per thread.
Summary:
This increases the odds that the boosted file (cpp file matching header)
will be ready. (It always enqueues first, so it'll be present unless
another thread indexes *two* files before the first thread indexes one.)
Reviewers: kadircet
Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64682
git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@366199 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed
