[c++] Enable project wide C++17 Support

[ShadowBearVR]

This change updates the C++ language version to C++17, project wide. Previously, C++14 was used.

The same update is being made to OpenTitan via lowRISC/opentitan#27530.

[cfrantz]

Don't we also need to add this to .bazelrc?

# https://opentitan.org/book/doc/contributing/style_guides/c_cpp_coding_style.html#c-version specifies
build --action_env=BAZEL_CXXOPTS="-std=gnu++17"
build --cxxopt='-std=gnu++17'
build --conlyopt='-std=gnu11'

[luismarques]

Don't we also need to add this to .bazelrc?

# https://opentitan.org/book/doc/contributing/style_guides/c_cpp_coding_style.html#c-version specifies
build --action_env=BAZEL_CXXOPTS="-std=gnu++17"
build --cxxopt='-std=gnu++17'
build --conlyopt='-std=gnu11'

What do you mean? The Ibex repo itself doesn't use Bazel. That was added on lowRISC/opentitan#27530 for the OT side of things.

[cfrantz]

What do you mean? The Ibex repo itself doesn't use Bazel. That was added on lowRISC/opentitan#27530 for the OT side of things.

NVM; I though it was for opentitan/master; I didn't realize this was for Ibex.