For whart in globals enum delphi_type, variosly mought be such :
enum fastcall_type {
FCT_MSC, /* MS 16-/32-bit fastcall (ax,dx,cx / ecx,edx) */
#if OWFC_SUPPORT
FCT_WATCOMC, /* OW register calling convention (eax, ebx, ecx, edx) */
#endif
#if AMD64_SUPPORT
FCT_WIN64, /* Win64 fastcall convention (rcx, rdx, r8, r9) */
#endif
FCT_DELPHI /* delphi fastcall convention (eax, edx, ecx ) */
};
And in ParseParams doubling line with proc->sym.langtype == LANG_DELPHICALL.