Revert recent GLSL slot counting fiasco.

Revert recent GLSL slot counting fiasco.

I apparently broke mark_whole_variable in ir_set_program_inouts.
It was passing a type that wasn't var->type, so the wrapper didn't
work out.  It's all broken, revert it and start over.

Fixes all kinds of things on other drivers.

Revert "glsl: Make is_fixed_function_array actually check for varyings."

This reverts commit 42699e12711668a142b7acf11c168cf4301c1295.

Revert "glsl: Mark whole variable used for ClipDistance and TessLevel*."

This reverts commit 5c580e64cc206ab160e1767c42e4d6c81f67da4d.

Revert "glsl: Override the # of varying slots for ClipDistance and TessLevel*."

This reverts commit 8b5749f65ac434961308ccb579fb8a816e4f29d5.

Revert "glsl: Create and use a new ir_variable::count_attribute_slots() wrapper."

This reverts commit 6aa5cb34d03765b7be8611aa516bc201bd337f73.