The public symbol file NTKRPAMP.PDB for the original release of Windows 10 tells that the kernel is built with the WHEA_X.H header at


and draws from it the following type definitions:

Line Number Type NTDDK.H NTOSP.H
43 enum _WHEA_ERROR_TYPE 16111 51028
53 union _WHEA_ERROR_PACKET_FLAGS 16121 51038
66 enum _WHEA_ERROR_PACKET_DATA_FORMAT 16134 51051
123 struct _WHEA_ERROR_PACKET_V2 16191 51108

The header WHEA_X.H is not known in any Device Driver Kit (DDK) or Windows Driver Kit (WDK).