Update prebuilt Clang to build 4630689.

Built from version 6.0.1
based on r316199.

Bug: http://b/73127367
Test: N/A
Exempt-From-Owner-Approval: my branch
Change-Id: I5b379dce9f17884ce895e805406d49306582a384
(cherry picked from commit be69b85315ed8c469bd8a48e49a5acd2e4345c46)
2315 files changed