[Dev] SIG-Proposal-Tools and Toolchain

Hello, Here's the SIG proposal for Tools and Tool Chain. The goal of the SIG is to keep assessing new toolchains and toolsets for integration into OpenHarmonyOS mainstream, starting with LLVM. The lead maintainer of this SIG is Bernhard Rosenkraenzer ( bernhard.rosenkraenzer.ext@huawei.com<mailto:bernhard.rosenkraenzer.ext@huawei.com> ). Detailed proposal is attached. Thank you. Best Regards, Jianyu Liu Warsaw Research Center [w6]