Update prebuilt Clang to r353983c1.

clang 9.0.3 (based on r353983c1) from build 6052599.

Bug: 145023753
Test: N/A
Change-Id: I0baf62a048d6139ed56d57e7a97b3aee7d9c4839
Merged-In: I0baf62a048d6139ed56d57e7a97b3aee7d9c4839
(cherry picked from commit a1163ec7741af3c6b1ff14cc10319b5a059049b2)
2394 files changed