When I tried to compile OpenSSH portable version 8.0 from source without OPENSSL_HAS_ECC defined, caught undefined reference error to kex_ecdh_keypair(), kex_ecdh_dec(), kex_ecdh_enc() functions in kexgen.c; All those functions needed to be under predefined macro OPENSSL_HAS_ECC because KEX_ECDH_SHA2 exists only under this macro. Raised a pull-request for Portable version for code reference and changes needed. https://github.com/openssh/openssh-portable/pull/128
This was fixed by https://github.com/openssh/openssh-portable/commit/97370f6c2c3b825f8c577b7e6c00b1a98d30a6cf (after 8.0) which adds no-op implementations of those functions without adding the added maintenance of those ifdefs.
closing resolved bugs as of 8.6p1 release