Merge branch 'jbolz_pipeline_barrier_1998' into 'master'

Put point vertex coordinates in [-.999, .999] rather than [-0.999, 1.0]

Fixes #236 

See merge request !355
diff --git a/external/vulkancts/modules/vulkan/memory/vktMemoryPipelineBarrierTests.cpp b/external/vulkancts/modules/vulkan/memory/vktMemoryPipelineBarrierTests.cpp
index 514a511..bfb66d7 100644
--- a/external/vulkancts/modules/vulkan/memory/vktMemoryPipelineBarrierTests.cpp
+++ b/external/vulkancts/modules/vulkan/memory/vktMemoryPipelineBarrierTests.cpp
@@ -6382,7 +6382,7 @@
 				"layout(location = 0) in highp vec2 a_position;\n"
 				"void main (void) {\n"
 				"\tgl_PointSize = 1.0;\n"
-				"\tgl_Position = vec4(1.999 * a_position - vec2(0.999), 0.0, 1.0);\n"
+				"\tgl_Position = vec4(1.998 * a_position - vec2(0.999), 0.0, 1.0);\n"
 				"}\n";
 
 			sources.glslSources.add("vertex-buffer.vert")
@@ -6398,7 +6398,7 @@
 				"void main (void) {\n"
 				"\tgl_PointSize = 1.0;\n"
 				"\thighp vec2 pos = vec2(gl_VertexIndex % 256, gl_VertexIndex / 256) / vec2(255.0);\n"
-				"\tgl_Position = vec4(1.999 * pos - vec2(0.999), 0.0, 1.0);\n"
+				"\tgl_Position = vec4(1.998 * pos - vec2(0.999), 0.0, 1.0);\n"
 				"}\n";
 
 			sources.glslSources.add("index-buffer.vert")