R600: fix PHI value adding in the structurizer

Otherwise we sometimes produce invalid code.

Patch by: Christian König

Signed-off-by: Christian König <christian.koenig@amd.com>
Tested-by: Michel Dänzer <michel.daenzer@amd.com>
R600: fix loop analyses in the structurizer

Patch by: Christian König

Intersecting loop handling was wrong.

Signed-off-by: Christian König <christian.koenig@amd.com>
Tested-by: Michel Dänzer <michel.daenzer@amd.com>
R600: rework flow creation in the structurizer v2

This fixes a couple of bugs and incorrect assumptions,
in total four more piglit tests now pass.

v2: fix small bug in the dominator updating

Patch by: Christian König

Signed-off-by: Christian König <christian.koenig@amd.com>
R600: Dump the function name when TargetLowering::LowerCall() fails

Also output a more useful error message.

NOTE: This is a candidate for the Mesa stable branch
ReleaseNotes: Add section for R600 backend