* Enforce layering_check in Bazel build rules.
Enforcing layering_check ensures that the Build targets do not rely on
transitive dependencies. See
https://github.com/bazelbuild/bazel/pull/11440 for a detailed
description of the feature.
We also do a style pass on the build files, ensuring that common linters
are happy with it.
* Add .bazelversion file and fix build_defs.bzl.
We fix build_defs.bzl to work on Bazel 5.0.0.
This CL moves the files in opt/ to consistenly be under the opt::
namespace. This frees up the ir:: namespace so it can be used to make a
shared ir represenation.
Re-formatted the source tree with the command:
$ /usr/bin/clang-format -style=file -i \
$(find include source tools test utils -name '*.cpp' -or -name '*.h')
This required a fix to source/val/decoration.h. It was not including
spirv.h, which broke builds when the #include headers were re-ordered by
clang-format.
