Issue 161130.2: Add DW_AT_encoding to the attribute list for DW_TAG_enumeration_type
Section Appendix A, pg 255
It is allowed to have a DW_AT_byte_size on a DW_TAG_enumeration_type,
but not DW_AT_encoding. To describe both size and encoding one needs to
use a DW_AT_type pointing to a base type that represents the "underlying type".
For languages where enumerations don't have an underlying type, or for
strongly typed enums it is easier to attach the encoding directly than
adding and indirection to a base type.
Add DW_AT_encoding to the attribute list for DW_TAG_enumeration_type.
Use DW_AT_type if encoding of base tpe is needed.