Remove stale clang prebuilts.

Removing:
clang-2812033
clang-3362437
clang-3957855
clang-3960126
clang-3977809

Test: N/A
Change-Id: Icfd9d81fd237654b7e4c36861a3e79ee55316f36
5651 files changed
tree: 86fa4f3c4fc15be5d19b2ac0a63b2a41dae637a9
  1. clang-3289846/
  2. clang-3859424/
  3. clang-4053586/
  4. clang-stable/
  5. OWNERS