tests/shader_runner: Explicitly require UAV load support.

The used UAV formats are explicitly added in the [require] section of
every test that uses them.

Some of these tests were failing on Intel UHD graphics 770 because of
missing support for additional UAV load types, explicitly requiring
these formats allows these tests to be skipped.

tests/hlsl/uav-rwbuffer.shader_test

@@ -164,6 +164,10 @@ float4 main() : sv_target1
     return 0;
 }
 
+
+[require]
+shader model >= 5.0
+
 [uav 1]
 format r32g32b32a32-sint
 size (buffer, 2)