* CECPQ2b will use SIKE/p434 instead of SIKE/p503
* KEM uses SHA256 instead of HMAC-256
* implements new starting curve: y^2=x^3 + 6x^2 + x
* adds optimized implementation for aarch64
* adds optimized implementation for AMD64
which do not support MULX/ADOX/ADCX
* syncs the SIKE test code with the NIST Round 2
specification.
* removes references to field size from variables
names, tests and defines.
Change-Id: I5359c6c62ad342354c6d337f7ee525158586ec93
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/36704
Reviewed-by: Adam Langley <agl@google.com>