52cf8e44880bcf614068b66b63393aa8da1edd76 (2013) introduced the VK_PPC_TLSGD workaround to prevent unconditional reference to _GLOBAL_OFFSET_TABLE_ in ELFObjectWriter. e2b355d651ed8f2cbe61672c4c39b6419e471265 (2015) removed the `_GLOBAL_OFFSET_TABLE_` hack for the generic VK_TLSGD, making the VK_PPC_TLSGD workaround unneeded.