This patch series introduces multilib support for Espressif XTENSA chips in gcc. The addition of the "-mdynconfig=" option was necessary because the existing environment variable XTENSA_GNU_CONFIG cannot be utilized for implementing multilib. This is because multilib operates with gcc options rather than environment variables.
It is not possible to use full path in "-mdynconfig=" because it could be different on users machines and because multilib syntax already reserves the directory delimiter character. So, it designed to contain dynconfig filename which would not change in toolchain. Also, the XTENSA_GNU_CONFIG environment variable usage was changed to include both the dynconfig file fullpath or dynconfigs directory. This change was made to overcome the limitations of modifying LD_LIBRARY_PATH on macOS host machines.
