Purpose :

According to GLSL SPEC 4.6 ( 4.4.1.4 Compute Shader Inputs), for compute shader input qualifiers, we should declare such qualifiers with same values in the same shader (local_size_x, y and z).
"If such a layout qualifier is declared more than once in the same shader, all those declarations must set the same set of local work-group sizes and set them to the same values; otherwise a compile-time error results."

Why this fix:

If we manually set "local_size_x = 1" and directly following a declaration like "local_size_x = 2", this would not be detected. That is because currently we treat all the '1' as default value and could not restrictly detect whether those are default values.

Test case:
......
layout(local_size_x=1) in;
layout(local_size_x=2) in;
......

So I add test cases for this fix:
1. set local_size_y = 1 => success
2. set local_size_y = 2 => error
3. set local_size_y = 1 => success

The order of error checking was not quite being correct (maybe there is no correct
ordering, when many checks must be done and they affect each other).
So, check for block-name reuse twice.

Update spirv-tools and spriv-headers known good.

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.