Code refine

Reduce the number of cycles.

Sync code

Sync code from KhronosGroup/glslang master

Also fixes, in practice, https://github.com/KhronosGroup/GLSL/issues/83.
When the specification language is correctly created, glslang can be
revisited for correctness.  In the meantime, this seems like the best
"bug" to have relative to the specification.

Memory qualifiers are only relevant to parameters when they apply
to what the argument points to, as otherwise the argument is copied.

This leaves the fix from #1870 in place, and then more correctly
ignores memory qualifiers when something will be passed by copy.

Initialize variable to avoid uninitialized variable warnings in Clang

In the current version of the code on non-debug builds these cases
will fallthrough, since assert is a no-op, and eventually make a call
passing in |op| which hasn't been initialized. clang is currently
throwing a warning about this behaviour when integrating downstream.

This patch changes the behaviour, so that in any branch that has an
assert now has a return nullptr, to indicate failure after it and
avoid the uninitialized variable usage.

GL_NV_integer_cooperative_matrix support

BUILD.gn: Add missing HLSL files.

Dereference any array type before expanding root-level SSBO members

GN build (for Chromium): enable HLSL in dependents.

The previous fix for this only enabled HLSL internally in glslang which
means that dependent using HLSL, for example shaderc, failed
compilation.

If we don't do this then we get reflection output like so:

ArrayedBind[0].a.a: offset 0, type 1406, size 1, index 4, binding -1, stages 0
ArrayedBind[0].a.b: offset 4, type 1406, size 1, index 4, binding -1, stages 0
ArrayedBind[0].b.a: offset 4, type 1406, size 1, index 4, binding -1, stages 0
ArrayedBind[0].b.b: offset 8, type 1406, size 1, index 4, binding -1, stages 0
ArrayedBind[0].b: offset 4, type 1406, size 1, index 4, binding -1, stages 1

When the outer reflection loop that calls blowUpActiveAggregate incorrectly iterates over the struct members.

GN build (for Chromium): enable HLSL

GLSL: Inherit memory qualifiers, both declaratively and in execution.

Fixes #1870, probably others.

Fix conformance with -Wextra-tokens

Web:  Create a very small-footprint glslang for web use.

Saved about 21K, size down to 380K of MSVC x86 code.
Fixed one bug that needs to be looked at on the master branch:
The test for needing a Vulkan binding has a bug in it, "!layoutAttachment"
which does not mean "no layoutAttachment", because that is non-zero.
This is why some test and test results changed.

added a few more HLSL flag tests.  This was mostly focused on the SPV generator.
Saves about 17K.

Saves about 6.5K

Saves 2.5K, and design is better.

Saves another 20K.

This saves another 40K of x86 binary, which is about 13% of the target size.

Saves about 9K.

About 60K smaller (20% the target size is these units of 300K).
Over 300 fewer #ifdef.

This adds a new glslang.m4 file that needs to be processed by m4 to get
the glslang.y file needed by bison.  See comment in glslang.m4 for more
detail.

This updates the updateGrammar script to do the .m4 -> .y processing,
to conditionally exclude grammar not needed for the web build.

About 50 fewer #ifdefs.
About 14K smaller.
Note, the base size is ill-defined due to optimizer settings (size vs. performance),
compression, and target architecture.  Some recent %'s are accidentally reported as
3X the real savings.  Early %'s were accurate.  What matters though is that each
step got worthwhile gains, and what the final size ends up being.