Signed-off-by: Anton Khirnov <anton@khirnov.net>

This reverts commit f8bed30d. The reason
for this is that the overlap filter, which runs after IDCT, should run
on unclamped values, and thus IDCT and put_pixels() cannot be merged if
we want to attempt to be bitexact.

Signed-off-by: Mans Rullgard <mans@mansr.com>

Merging these functions allows merging some loops, which makes the
results (particularly after SIMD optimizations) much faster.