Everything before crypto/ec.

Change-Id: Icbfab8e4ffe5cc56bf465eb57d3fdad3959a085c
Reviewed-on: https://boringssl-review.googlesource.com/3401
Reviewed-by: Adam Langley <agl@google.com>

This is an initial cut at aarch64 support. I have only qemu to test it
however—hopefully hardware will be coming soon.

This also affects 32-bit ARM in that aarch64 chips can run 32-bit code
and we would like to be able to take advantage of the crypto operations
even in 32-bit mode. AES and GHASH should Just Work in this case: the
-armx.pl files can be built for either 32- or 64-bit mode based on the
flavour argument given to the Perl script.

SHA-1 and SHA-256 don't work like this however because they've never
support for multiple implementations, thus BoringSSL built for 32-bit
won't use the SHA instructions on an aarch64 chip.

No dedicated ChaCha20 or Poly1305 support yet.

Change-Id: Ib275bc4894a365c8ec7c42f4e91af6dba3bd686c
Reviewed-on: https://boringssl-review.googlesource.com/2801
Reviewed-by: Adam Langley <agl@google.com>

(With minor bn/generic.c revamp.)

(Imported from upstream's 56df92efb6)

Change-Id: I9d85cfde4dfb29e64ff7417f781d0c9f1685e905
Reviewed-on: https://boringssl-review.googlesource.com/2780
Reviewed-by: Adam Langley <agl@google.com>

bl and bh are never used by macros if either BN_UMULT_LOHI or
BN_UMULT_HIGH are defined.

Change-Id: I7fdd45014a6b78cc586b5223396e09bc213608a5
Reviewed-on: https://boringssl-review.googlesource.com/2105
Reviewed-by: Adam Langley <agl@google.com>

generic.c still needs to include generic implementations in Win64.
Those are currently done with inline assembly and won't work on
MSVC.

Change-Id: Ifeb5470872d8c97b2ccffeae6f3ccb5661051de3
Reviewed-on: https://boringssl-review.googlesource.com/2102
Reviewed-by: Adam Langley <agl@google.com>

We were building the NASM flavor with MASM which is why it didn't work. Get the
MASM output working: cpuid and cmove are not available in MASM unless the file
declares .686. Also work around MASM rejecting a very long line in SHA-256.

The follow-up change will get the NASM flavor working. We should probably use
that one as it's documented as supported upstream. But let's make this one
functional too.

Change-Id: Ica69cc042a7250c7bc9ba9325caab597cd4ce616
Reviewed-on: https://boringssl-review.googlesource.com/2091
Reviewed-by: Adam Langley <agl@google.com>

Initial fork from f2d678e6e8 (1.0.2 beta).

(This change contains substantial changes from the original and
effectively starts a new history.)