fsp_srv: Emplace entries first when building index instead of emplacing last

gl_shader_decompiler: Reserve element memory beforehand in BuildRegisterList()

vfs: Add VfsFilesystem and fix RealVfs* implementations

maxwell_3d: Ignore macros that have not been uploaded yet.

* Implement BC5/DXN2 (#996)

- Used by Kirby Star Allies.

* Implement BC5/DXN2 SNORM

UNORM for Kirby Star Allies
SNORM for Super Mario Odyssey

gl_rasterizer_cache: Avoid iterator invalidation issues within InvalidateRegion()

Avoids potentially perfoming multiple reallocations when we know the
total amount of memory we need beforehand.

A range-based for loop can't be used when the container being iterated
is also being erased from.

gl_shader_decompiler: Declare predicates on use.

gl_rasterizer_cache: Use std::vector::assign vs resize() then copy for the non-tiled case

Implement VertexAttribute::Size::Size_16_16_16_16 and PrimitiveTopology::Points.

gl_rasterizer: Do not render when no render target is configured.

- Used by Kirby Star Allies.

common/color: Minor cleanup

gl_rasterizer_cached: Implement RenderTargetFormat::B5G6R5_UNORM.

It's generally easier to follow code using conditionals that operate in
terms of the true case followed by the false case (no chance of
overlooking the exclamation mark).

resize() causes the vector to expand and zero out the added members to
the vector, however we can avoid this zeroing by using assign().

Given we have the pointer to the data we want to copy, we can calculate
the end pointer and directly copy the range of data without the
need to perform the resize() beforehand.

vector_math: Use variable template version of is_signed in Vec classes

- Used by Super Mario Odyssey (in game).

- Used by Super Mario Odyssey (in game).

- Used by Super Mario Odyssey (when going in game).

- Used by Super Mario Odyssey (in game).

This is only ever read from, so we can make the data it's pointing to
const.

gl_shader_decompiler: Stub input attribute Unknown_63.

Service/Account: stub LoadImage function

- Used by Super Mario Odyssey.

gl_shader_decompiler: Let OpenGL interpret floats.

maxwell_3d: Use correct const buffer size and check bounds.