[LLDB][NFCI] Teach LLDB to read the DW_AT_LLVM_tag_offset attribute for variables (#181011) LLVM added support for emitting the tagging offset of a variable for hwasan/memtag-stack using the DW_AT_LLVM_tag_offset attribute in dabd262. This patch teaches LLDB to read this attribute. GitOrigin-RevId: 1268e7630d3072c990d6d1cd9f84ef8c7041d0fa