This change includes C versions of some of the functions from the x86-64
P-256 code that are currently implemented in assembly. These functions
were part of the original submission by Intel and are covered by the ISC
license.
No semantic change; code is commented out.
Change-Id: Ifdd2fac6caeb73d375d6b125fac98f3945003b32
Reviewed-on: https://boringssl-review.googlesource.com/12861
Reviewed-by: Adam Langley <agl@google.com>