remove rust deps on clang prebuilts

Prebuilt modules for some clang tools were created in aosp/2746469, but they do not exist for darwin builds. Adding the same modules in prebuilts/clang/host/darwin-x86/Android.bp results in duplicate module names. Instead we can just get a path to these files directly in Soong.

Test: CI
Test: https://android-build.googleplex.com/builds/abtd/run/L90700000963131594
Change-Id: I620cfd7b1ab34bd0959feea562d599b963717198