When constructing a matrix from another matrix with smaller dimensions,
there's no need to extract the scalars out of columns and rebuild the
resulting matrix from scalars - instead, we can just construct shorter
vectors with OpShuffle and combine them to the final result.

This keeps the common casts such as mat3(mat4) in vector registers,
which may improve performance for some GPUs, and cleans up output of
translation tools like SPIRV-Cross.

Fixes #1412.

Implement GL_EXT_shader_16bit_storage and GL_EXT_shader_8bit_storage …

These introduce limited support for 8/16-bit types such that they can only be accessed in buffer memory and converted to/from 32-bit types.

Contributed from Khronos-internal work.

(If there is a bias issue, we need to discover what it is.)

Add support for GL_EXT_samplerless_texture_functions

SPV: Add option to print disassembly in standard form using SPIRV-Tools.

This results in better error recovery, including fewer
crashes on badly formed PP input.

Constant.cpp will throw a floating point divide by zero if floating point exceptions are enabled in Win32 causing the program to crash. This fix manually checks the right-hand argument of the division and sets appropriate Infinity, Negative Infinity, or NAN as if the floating point exceptions were disabled.

Include spirv-remap.exe in AppVeyor artifacts

script: Improve update sources script

- remove unused variable to pass pylint
- Use another approach to detect if known-good remote is already
  present to avoid the need for "ignore following errors" message.

Build: Make literal casting have fewer warnings and be more consistent.

Add support for OpConstantNull and OpConstantSampler to spirv-remap

Fixes issue #1408

This reverts commit ebec9094.

Khronos decided glslang was originally correct, and the specifications
are incorrect.

Take into account arrays of opaque types with --auto-map-bindings

TDefaultIoResolverBase::reserveSlot and getFreeSlot now have a size
parameter to reserve a range of bindings. This is used by
TDefaultIoResolver::resolveBinding to reserve a continuous range when
the type is an array and the target API is GL.

Update spirv-tools known-good

Includes the following spirv-opt improvements:

Preserve inst-to-block and def-use in passes.
Add store for var initializer in inlining.
Handle types with self references.

Relax a stringToDouble test for, OSX AppleClang 9.1

1e-323 was flushed to zero.
1e-308 is also flushed to zero.
Use 1e-307 instead, which still satisfies the test intent.

Fixes #1400

The major version number was bumped in the previous commit to support
this.

Fix several signed/unsigned comparison compile warnings.

Update spirv-tools known-good.