Update prebuilt Clang to r416183b1 (12.0.7).

clang 12.0.7 (based on r416183b1) from build 7485623.

Bug: http://b/189328402
Test: N/A
Change-Id: Iebdc8f0e443531c8139be17a8a6e47825a41139d
5205 files changed