testing: Cut render-* test resolution in half to speed up testing (#2131)

The time it takes to run a full testsuite was slowly creeping up to an
inconvenient time on CI. The most expensive test are the `render-*`
tests. Cut all of their resolutions in half to speed up CI runs.

Update a lot of reference images.

But after updating the ref images we need to fully pass CI (and pass
on my work machine and my personal laptop), I could see that there
were a number of `testsuite/render-*/ref/*.exr` files that did NOT
get updated in this process -- we must conclude that they are old
references that are no longer needed, so I deleted them.

I also noticed that testsuite/render-material-layer had no ref images
updated, and some git investigation reveals that this test that was
added in 2017 was NEVER in testing.cmake and thus never ran in CI
at all. So just remove it.

Signed-off-by: Larry Gritz <lg@larrygritz.com>

Author: lgritz

src/cmake/testing.cmake

@@ -374,7 +374,7 @@ macro (osl_add_all_tests)
                 render-mx-sheen
                 render-mx-medium-vdf
                 render-mx-medium-vdf-glass
-		render-microfacet render-oren-nayar
+                render-microfacet render-oren-nayar
                 render-spi-thinlayer
                 render-uv render-veachmis render-ward
                 render-raytypes

testsuite/render-background/ref/out-macos-alt.exr

@@ -11,4 +11,4 @@
 idiff_program = "idiff"
 
 outputs = [ "out.exr" ]
-command = testrender("-r 320 240 -aa 4 --options statistics:level=1 scene.xml out.exr")
+command = testrender("-r 160 120 -aa 4 --options statistics:level=1 scene.xml out.exr")

testsuite/render-background/ref/out-optix-alt.exr

@@ -9,6 +9,6 @@
 hardfail = 0.035
 
 outputs = [ "out.exr" ]
-command = testrender("-r 256 256 -aa 4 --llvm_opt 13 bumptest.xml out.exr")
+command = testrender("-r 128 128 -aa 4 --llvm_opt 13 bumptest.xml out.exr")
 
 # Note: we pick this test arbitrarily as the one to verify llvm_opt=13 works