Use sized integer types rather than unsigned char/int/long. The latter
two are especially a mess as they're both used in lieu of uint32_t.
Sometimes the code just blindly uses unsigned long and sometimes it uses
unsigned int when an LP64 architecture would notice.

Change-Id: I4c5c6aaf82cfe9fe523435588d286726a7c43056
Reviewed-on: https://boringssl-review.googlesource.com/4952
Reviewed-by: Adam Langley <agl@google.com>

Everything else.

Change-Id: Iac02b144465b4e7b6d69ea22ff2aaf52695ae732

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>

Initial fork from f2d678e6e8 (1.0.2 beta).

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