GL_ARB_ES3_1_compatibility extension not supported

For `gl_HelperInvocation` in desktop GLSL this was added in [GL_ARB_ES3_1_compatibility ](https://registry.khronos.org/OpenGL/extensions/ARB/ARB_ES3_1_compatibility.txt) which became core in GLSL version 450. The extension though is written against GL 4.4 and so should be usable in a GLSL version 440 shader with the appropriate `#extension`.

It looks like glslang currently doesn't allow this extension: https://godbolt.org/z/j49Po3oW8

```
#version 440 core

#extension GL_ARB_ES3_1_compatibility : require

layout(binding = 0) uniform foo
{
vec4 data;
} bar;

layout(location = 0) out vec4 col;

void main() {
col = gl_HelperInvocation ? vec4(0, 1, 0, 1) : vec4(1, 0, 0, 1);
}
```

As this produces an error:

```

:3: '#extension' : extension not supported: GL_ARB_ES3_1_compatibility
:3: '#extension' : extra tokens -- expected newline
:3: '' : compilation terminated
3 compilation errors. No code generated.
```

Hopefully I've understood the track of these extensions correctly and this should be allowed.

Reproduce the shader from the issue in the linked Godbolt example using glslang. Trace how glslang handles #extension declarations and GLSL version compatibility, then verify that GL_ARB_ES3_1_compatibility is accepted for #version 440 and that the shader compiles without the reported errors.

Written by the indexing model from the issue text.