Make deps: Fix compilation error on CentOS

There were two issues.

First is related on ISPC's CMake configuration forcing C and C++
compilers to be clang and clang++. This goes against of desired
behavior when we use our own compiled clang compilers.

The second issue was related on linker failure: CLang libraries
are linked statically, and they need some of C++ 11 STL symbols
which are coming from libstdc++.

Differential Revision: https://developer.blender.org/D8258

Build: fix stack linker warning with ffmpeg on macOS

The ff_cfhd_init_vlcs() function was using a lot of stack space, which
made linker on macOS unhappy. Using heap allocation allows to silence
the warning without causing other side-effects.

Kept the patch enabled for all platforms to avoid difference in behavior
and performance on different platforms, which could make certain types
of investigation very tricky.

Differential Revision: https://developer.blender.org/D8248

CMake: Fix spelling of Embree passed to find package

The spelling and capitalization of package name passed to find_package()
and find_package_handle_standard_args() needs to match.

Silences CMake warning about mismatch.

Differential Revision: https://developer.blender.org/D8247

BLI: Correct spin lock definition

The MSVC atomic function is defined for an unsigned type.

Not sure why this became an issue after switch to TBB by default,
maybe some CFLAGS changed to be more strict after that.

Make deps: Use own nasm for ffmpeg and x264

Fixes the warning: building for macOS, but linking in object file

Differential Revision: https://developer.blender.org/D8235

Make deps: Compile own version of nasm for Apple

The upstream version of nasm does not put version information to the
generated object files, which makes linker to show the following
warning:

building for macOS, but linking in object file

Using own patched version of nasm which puts required information to
the object file, making linker happy.

The plan is to either streamline the patch and provide it to the
upstream, or, it that takes too long, get an independent fix from the
upstream.

BLI: Fix mistake in SpinLock TBB migration

Copy-paste mistake.

Make deps: Fix compilation error of Python on macOS

The configuration was confused about gettext installed via Homebrew
and isysroot passed to Python's compilation but not to test programs.

After this change `import gettext` still works, but it is unclear how
to test it further,

Differential Revision: https://developer.blender.org/D8231

Make deps: Fixes for macOS platform

Set of fixes which had to be made in order to have dependencies built
on own laptop:

- Require bison as a dependent software. It is required by ISPC.

On macOS it is required to be installed via Homebrew. This is because
Bison from Xcode toolchain is too old.

- Made sure Boost is compiled using clang.

Without this gcc was used, and some unsupported command line argument
was passed to it.

- Modify OGG in a way which does in fact pull fixed sized types.
They are defined in stdint.h.

Without this fix FFmpeg will not detect presence of OGG because the
test program fails to compile.

- Force disable zstd compression and make wepb optional for the TIFF
library. Without this TIFF might pick up development libraries from
Homebrew.

Differential Revision: https://developer.blender.org/D8221

Fix alignment/size issue on ARM/RPi architecture

Addresses 964305 from Debian bug tracker.