nir: Print the components referenced for split or packed shader in/outs.

nir: Print the components referenced for split or packed shader in/outs.

Having 4 variables all called "gl_in_TexCoord0@n" isn't very informative,
much better to see:

decl_var shader_in INTERP_MODE_NONE float gl_in_TexCoord0 (VARYING_SLOT_VAR0.x, 1, 0)
decl_var shader_in INTERP_MODE_NONE float gl_in_TexCoord0@0 (VARYING_SLOT_VAR0.y, 1, 0)
decl_var shader_in INTERP_MODE_NONE float gl_in_TexCoord0@1 (VARYING_SLOT_VAR0.z, 1, 0)
decl_var shader_in INTERP_MODE_NONE float gl_in_TexCoord0@2 (VARYING_SLOT_VAR0.w, 1, 0)

v2: Handle arrays and structs better (by Timothy)

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>