btf_encoder: Add extra debug info for unsupported DWARF tags

Recently we got a report of DW_TAG_unspecified_type triggering this
warning:

[ 1413s]   BTF     .btf.vmlinux.bin.o
[ 1413s] Unsupported DW_TAG_unspecified_type(0x3b)
[ 1413s] Encountered error while encoding BTF.

Probably tag->type is zero, but would be great to have this offhand, add
that info to the error message.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
1 file changed