[Downstream Change] Arm Toolchain ID

[dcandler]

Since there are potentially different versions of the toolchain that can be built (e.g. Arm Toolchain for Embedded and Arm Toolchain for Linux), we need a way to uniquely identify the toolchain from the version output, and differentiate from the upstream version. This can be done by appending an additional message:
Arm Toolchain ID: tag.

Where tag comprises a one letter code for the product:

• E for Embedded
• L for Linux

Followed by an identifier for the build such as build number.

This issue tracks the downstream changes to implement this, since it will cause the code to diverge from upstream.

[pawosm-arm]

Why can't we reuse already existing -DCLANG_VENDOR and -DFLANG_VENDOR CMake flags for this instead of adding new code?

[pawosm-arm]

Anything left to do here?

[dcandler]

Not currently, but now that the downstream change has been implemented this issue should track the ongoing maintenance burden, and any attempt to upstream the work so that the change can be removed.