* Make cc_toolchain_utils.bzl more reusable
By using getattr, the helper functions in this file can be reused in
rules that do not define all of the framework attributes, e.g. bootstrap
rules.
* Bootstrap make reproducibly on Linux and macOS
Uses the Bazel C/C++ toolchain to bootstrap make and ensure that the
resulting binary contains no absolute and thus non-hermetic paths.
Building make reproducibly helps with remote caching and removes the
dependency on a C compiler installed on the host.
Fabian Meumertzheim