core/crypto: Minor changes

service: Remove redundant #pragma once directives

These don't do anything within .cpp files (we don't include cpp files,
so...)

These functions should only be given trivially-copyable types.

This function doesn't directly depend on class state, so it can be
hidden entirely from the interface in the cpp file.

This doesn't modify member state, so it can be made const.

The benefit of std::string_view comes from the idea of avoiding copies
(essentially acting as a non-owning view), however if we're just going
to copy into a local variable immediately, there's not much benefit
gained here.

XCI and Encrypted NCA Support

 gl_shader_manager: Amend sign differences in an assertion comparison in SetShaderUniformBlockBinding()

This lets us indent the majority of the code and places the error case
first.

gl_shader_manager: Amend sign differences in an assertion comparison in SetShaderUniformBlockBinding()

Ensures both operands have the same sign in the comparison.

While we're at it, we can get rid of the redundant casting of ub_size to
an int. This type will always be trivial and alias a built-in type (not
doing so would break backwards compatibility at a standard level).

video_core: Remove unimplemented Start() function prototype

memory: Remove unused GetSpecialHandlers() function

 kernel/process: Use accessors instead of class members for referencing segment array

kernel/thread: Fix potential crashes introduced in 26de4bb5

This amends cases where crashes can occur that were missed due to the
odd way the previous code was set up (using 3DS memory regions that
don't exist).

gl_shader_decompiler: Remove unused variable in GenerateDeclarations()

Using member variables for referencing the segments array increases the
size of the class in memory for little benefit. The same behavior can be
achieved through the use of accessors that just return the relevant
segment.

This is just unused code, so we may as well get rid of it.

core/memory: Get rid of 3DS leftovers

gl_shader_manager: Make ProgramManager's GetCurrentProgramStage() a const member function

Given this has no definition, we can just remove it entirely.

This variable was being incremented, but we were never actually using
it.

This function doesn't modify class state, so it can be made const.

Removes leftover code from citra that isn't needed.

Added ability to change username & language code in the settings ui. Added IProfile::Get and SET::GetLanguageCode for libnx tests (#851)

 sink_details: std::move std::function instances 

service: Add migration services

math_util: Always initialize members of Rectangle

video_core: Make global EmuWindow instance part of the base renderer …

kernel: Move object class to its own source files

kernel/thread: Minor changes

input_common: minor changes

yuzu: Use Qt 5 signal/slots where applicable

kernel/vm_manager: Minor changes

vfs_vector: Minor changes

gl_shader_manager: Take ShaderSetup instances by const reference in UseProgrammableVertexShader() and UseProgrammableFragmentShader()

Makes the signal/slot connections type-safe instead of string-based.