r600/sb: do not convert if-blocks that contain indirect array access

r600/sb: do not convert if-blocks that contain indirect array access

If an array is accessed within an if block, then currently it is not known
whether the value in the address register is involved in the evaluation of the
if condition, and converting the if condition may actually result in
out-of-bounds array access. Consequently, if blocks that contain indirect array
access should not be converted.

Fixes piglits on r600/BARTS:
spec/glsl-1.10/execution/variable-indexing/
  vs-output-array-float-index-wr
  vs-output-array-vec3-index-wr
  vs-output-array-vec4-index-wr

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104143

Signed-off-by: Gert Wollny <gw.fossdev@gmail.com>
Cc: <mesa-stable@lists.freedesktop.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>