Update prebuilt Clang to r547379 (20.0.0). am: 0185529828

Original change: https://android-review.googlesource.com/c/platform/prebuilts/clang/host/darwin-x86/+/3471988

Change-Id: I69e3b9ff26ee7ca3dd140a4de0828f0022423374
Signed-off-by: Automerger Merge Worker <[email protected]>