glsl/ir: add param index to variable.

We have a requirement to store the index into the mesa parameterlist
for uniforms. Up until now we've overwritten var->data.location with
this info. However this then stops us accessing UniformStorage,
which is needed to do proper dereferencing.

Add a new variable to ir_variable to store this value in, and change
the two uses to use it correctly.

Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

src/compiler/glsl/ir.h

@@ -863,6 +863,14 @@ public:
        */
       int location;
 
+      /**
+       * for glsl->tgsi/mesa IR we need to store the index into the
+       * parameters for uniforms, initially the code overloaded location
+       * but this causes problems with indirect samplers and AoA.
+       * This is assigned in _mesa_generate_parameters_list_for_uniforms.
+       */
+      int param_index;
+
       /**
        * Vertex stream output identifier.
        */