kernel: Eliminate kernel global state

Port #3825 from Citra: "travis: share environment variables with Docker"

Shaders: Implemented IADD3

As means to pave the way for getting rid of global state within core,
This eliminates kernel global state by removing all globals. Instead
this introduces a KernelCore class which acts as a kernel instance. This
instance lives in the System class, which keeps its lifetime contained
to the lifetime of the System class.

This also forces the kernel types to actually interact with the main
kernel instance itself instead of having transient kernel state placed
all over several translation units, keeping everything together. It also
has a nice consequence of making dependencies much more explicit.

This also makes our initialization a tad bit more correct. Previously we
were creating a kernel process before the actual kernel was initialized,
which doesn't really make much sense.

The KernelCore class itself follows the PImpl idiom, which allows
keeping all the implementation details sealed away from everything else,
which forces the use of the exposed API and allows us to avoid any
unnecessary inclusions within the main kernel header.

gpu: Make memory_manager private

gl_rasterizer: Remove unused variables

hle/result: Make ResultVal's move constructor as noexcept

gl_shader_cache: Remove unused program_code vector in GetShaderAddress()

Given std::vector is a type with a non-trivial destructor, this
variable cannot be optimized away by the compiler, even if unused.
Because of that, something that was intended to be fairly lightweight,
was actually allocating 32KB and deallocating it at the end of the
function.

Makes the class interface consistent and provides accessors for
obtaining a reference to the memory manager instance.

Given we also return references, this makes our more flimsy uses of
const apparent, given const doesn't propagate through pointers in the
way one would typically expect. This makes our mutable state more
apparent in some places.

yuzu: Fix two stupid errors made in #1141

Many containers within the standard library provide different behaviors
based on whether or not a move constructor/assignment operator can be
guaranteed not to throw or not.

Notably, implementations will generally use std::move_if_noexcept (or an
internal implementation of it) to provide strong exception guarantees.
If a move constructor potentially throws (in other words, is not
noexcept), then certain behaviors will create copies, rather than moving
the values.

For example, consider std::vector. When a std::vector calls resize(),
there are two ways the elements can be relocated to the new block of
memory (if a reallocation happens), by copy, or by moving the existing
elements into the new block of memory. If a type does not have a
guarantee that it will not throw in the move constructor, a copy will
happen. However, if it can be guaranteed that the move constructor won't
throw, then the elements will be moved.

This just allows ResultVal to be moved instead of copied all the time if
ever used in conjunction with containers for whatever reason.

renderer_opengl: Implement a new shader cache.

yuzu: Fix input UI direction order for the right stick

kernel/error: Amend several error codes

shader_bytecode: fix SEL_IMM bitstring

vfs_real: Remove unused variable in CreateDirectoryRelative()

file_util: Correct return value in early exit of ReadFileToString()

core: Namespace all code in the arm subdirectory under the Core namespace

registered_cache: Get rid of variable shadowing in ProcessFiles()

Prevents compiler warnings.

hex_util: Replace logic_errors with LOG_CRITICAL

 svc: Return process title ID if queried in GetInfo()

debug_utils: Minor individual interface changes

PL:U Added SharedFonts loading via TTF

hid: Move core include to cpp file

core: Remove always true conditionals in Load()

set: Fixed GetAvailableLanguageCodes() to follow the max_entries

Rightnow, in games use GetAvailableLanguageCodes(), there is a WriteBuffer() with size larger than the buffer_size. (Core Critical core\hle\kernel\hle_ipc.cpp:WriteBuffer:296: size (0000000000000088) is greater than buffer_size (0000000000000078))

0x88 = 17(languages) * 8
0x78 = 15(languages) * 8

GetAvailableLanguageCodes() can only support 15 languages.
After firmware 4.0.0 there are 17 supported language instead of 15, to enable this GetAvailableLanguageCodes2() need to be used.
So GetAvailableLanguageCodes() will be caped at 15 languages.
Reference:
http://switchbrew.org/index.php/Settings_services

maxwell3d: Move FinishedPrimitiveBatch event after AcceleratedDrawBatch()