llvm_tools: refactor LLVM bisection tool

BUG=chromium:1081457
TEST=Verified locally.

Change-Id: Ic662a7bb697efb920a83255d3da87a0031e694ed
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2371502
Tested-by: Jian Cai <jiancai@google.com>
Reviewed-by: George Burgess <gbiv@chromium.org>
2 files changed