Fix struct offsets (DWARF v2 compatibility)
Fix struct offsets (DWARF v2 compatibility)

For DWARF v2, DW_AT_data_member_location is encoded as a set of operations. The member_offset is in that case a list that starts with an operation (typically DW_OP_plus_uconst), so member_offset[0] is not the offset.

This solves the kernel/poll test (issue #7885)
mbolivar/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,explora26/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,zephyriot/zephyr,ldts/zephyr,finikorg/zephyr,explora26/zephyr,nashif/zephyr,explora26/zephyr,kraj/zephyr,GiulianoFranchetto/zephyr,kraj/zephyr,ldts/zephyr,ldts/zephyr,Vudentz/zephyr,ldts/zephyr,punitvara/zephyr,zephyriot/zephyr,explora26/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,Vudentz/zephyr,Vudentz/zephyr,galak/zephyr,galak/zephyr,punitvara/zephyr,nashif/zephyr,explora26/zephyr,mbolivar/zephyr,mbolivar/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,finikorg/zephyr,mbolivar/zephyr,finikorg/zephyr,galak/zephyr,zephyriot/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,zephyriot/zephyr,kraj/zephyr,punitvara/zephyr,GiulianoFranchetto/zephyr,punitvara/zephyr,galak/zephyr,kraj/zephyr,mbolivar/zephyr,kraj/zephyr,punitvara/zephyr,nashif/zephyr,ldts/zephyr,zephyriot/zephyr,nashif/zephyr