Revert "Revert "GPUShaderCreateInfo for interface abstraction""

This reverts commit edee5a947b.

Fixes compilation error (Missing file BLI_float2.hh)

source/blender/gpu/shaders/gpu_shader_gpencil_stroke_frag.glsl

@@ -1,16 +1,18 @@
+#ifndef USE_GPU_SHADER_CREATE_INFO
 in vec4 mColor;
 in vec2 mTexCoord;
 
 out vec4 fragColor;
+#endif
 
 void main()
 {
   const vec2 center = vec2(0, 0.5);
-  vec4 tColor = vec4(mColor);
+  vec4 tColor = vec4(geometry_out.mColor);
   /* if alpha < 0, then encap */
-  if (mColor.a < 0) {
+  if (geometry_out.mColor.a < 0) {
     tColor.a = tColor.a * -1.0;
-    float dist = length(mTexCoord - center);
+    float dist = length(geometry_out.mTexCoord - center);
     if (dist > 0.25) {
       discard;
     }