Update clang prebuilts to clang-r365631

This commit updates clang prebuilts to clang-r365631.  This removes an
Android-specific patch in `path_utils.cc` and backports the `HandlePragma`
fix.

Test: OUT_DIR=out ./prebuilts/clang-tools/build-prebuilts.sh
Bug: 140110040
Change-Id: Iacf0f3fca0d2e3d4609356c8c0d41157edaeff57
2 files changed