Add command line args setting option for the GLSL validator executable

[w103csh]

I started using your extension for linting my shader code, and it worked great until I started using push constants in my shaders. Push constants are a SPIR-V only type, so it caused the extension to stop evaluating my shader code after it found a push constant block like this:

struct MaterialData {
    vec3 Ka;            // Ambient reflectivity
    vec3 Kd;            // Diffuse reflectivity
    vec3 Ks;            // Specular reflectivity
    float Shininess;    // Specular shininess factor
};

layout(push_constant) uniform PushBlock {
    MaterialData material;
} pushConstantsBlock;

The GLSL validator I am using supports code like above, but it requires the command line argument -V. I altered your extension so that it could handle command line arguments. This is what the pull request entails.

I thought I should make a PR in case you want the change.

• Note - The format of the error messages when using the -V argument is slightly different. It includes the file name instead of just a number like so:
  ERROR: color.vert:15: '' : syntax error, unexpected IDENTIFIER
  Instead of:
  ERROR: 0:15: '' : syntax error, unexpected IDENTIFIER
  This is why the regex for the error parser was changed.

[w103csh]

The correct command line argument for my example above is actually --spirv-val not -V for the validator I linked to in the initial PR comment. Just an FYI.

[ghost]

Thanks for the pull request, I will test this out the next few days and then create an update on the marketplace. This could also fix #1

[w103csh]

Just downloaded from the marketplace and it seems to work right for the SPIR-V flag. Cheers!!!