Add script to crank test shaders through spirv-val

Reverse order of setShiftBindingForSet parameters

Appveyor: auto deploy build artifacts to GitHub Releases

Fix external update script for GitHub SSH access

See merge request !30

Per feedback on PR #1111, this reverses the order of the parameters for the setShiftBinding API.

It is now:

    void TShader::setShiftBindingForSet(TResourceType res, unsigned int base, unsigned int set);

This script will crank a supplied set of glslang test shaders through the
spirv-val tool, reporting on the results.

There are some important things to note:

* Like 'runtests', this must be invoked from the 'Test' subdirectory.

* This is mostly useful on the hlsl.* tests, although it is not strictly
limited to those.  The reason is that most of the glsl tests either contain
validation error cases, and so fail to compile, or are not using a #version
compatible with producing SPIR-V modules.

* Some tests, such as negative tests, or most of the glsl tests, have
intentional compilation errors.  This script treats that as OK.  Failures
are successfully compiling shaders which proceed to fail spirv-val.

* spirv-val is looked for in either the External directory, or if not
found there, in a sibling directory of glslang, and if not found there
either, in /usr/local/bin.

* There are a bunch of command line options.  ./validate-shaders.sh --help
will describe them.

Some examples to try:

   ./validate-shaders.sh hlsl.*   # exercise all hlsl.* tests.
   ./validate-shaders.sh --terse hlsl.*  # same, but tersely.

   # dump validator results for problems in something.frag:
   ./validate-shaders.sh --quiet --dump-val something.frag

Pushing a commit to the master branch will trigger a build on
Appveyor. If the build is successful, the artifacts will be
collected and pushed to GitHub Releases, under the "master-tot"
release.

Modify the update_glslang_sources_khr.py script to use SSH protocol for
GitLab rather than HTTPS

Remapper: Fix strip algo when strip ranges overlap

To handle sparse assignments, don't check maxCombinedTextureImageUnits.

Fix gitlab known-good to correct commits for 1.1 SDK

See merge request !28

Also add update_glslang_sources_khr.py

Fixes issue !27.

Add python3 compatibility to update_glslang_sources.py

Both debug and release clang builds have segfaulted on recent
changes, non deterministically, while doing the single/multi-thread
test all test files. Removing recent test files, to see if it gives
a clue.

GLSL: Fold constant SHRT_MIN/INT_MIN/LLONG_MIN % -1 to 0.

The previous merge needs this hole filled, but filling
it as a separate commit.

GLSL: Check for implicit inner dimension in array of atomic_uint.

Preprocessor: Evaluate INT_MIN % -1 to 0.

Restore original canImplicitlyPromote implementation

See merge request !26

This change restores original canImplicitlyPromote implementation in
case the explicit type extension wasn't requested.

Update spirv-tools known-good