SPIR-V assembly tests require Invocations in Geometry shaders

Validation layers are complaining about the lack of Invocation count in
several of the geometry spirv assembly tests.

Affects: dEQP-VK.spirv_assembly.instruction.graphics.*_geom

Components: Vulkan

VK-GL-CTS issue: 1862

Change-Id: I3c3f44574bef0ad2d61b27f0b3d94f9e24924a92
diff --git a/external/vulkancts/modules/vulkan/spirv_assembly/vktSpvAsmGraphicsShaderTestUtil.cpp b/external/vulkancts/modules/vulkan/spirv_assembly/vktSpvAsmGraphicsShaderTestUtil.cpp
index e009a83..ae8a41f 100644
--- a/external/vulkancts/modules/vulkan/spirv_assembly/vktSpvAsmGraphicsShaderTestUtil.cpp
+++ b/external/vulkancts/modules/vulkan/spirv_assembly/vktSpvAsmGraphicsShaderTestUtil.cpp
@@ -834,6 +834,7 @@
 		"OpMemoryModel Logical GLSL450\n"
 		"OpEntryPoint Geometry %BP_main \"main\" %BP_out_gl_position %BP_gl_PrimitiveID %BP_gl_in %BP_out_color %BP_in_color ${IF_entrypoint:opt} \n"
 		"OpExecutionMode %BP_main Triangles\n"
+		"OpExecutionMode %BP_main Invocations 1\n"
 		"OpExecutionMode %BP_main OutputTriangleStrip\n"
 		"OpExecutionMode %BP_main OutputVertices 3\n"
 		"${execution_mode:opt}\n"
@@ -1465,6 +1466,7 @@
 	if (useGeometry)
 	{
 		combinedModule <<	"OpExecutionMode %geom_main Triangles\n"
+							"OpExecutionMode %geom_main Invocations 1\n"
 							"OpExecutionMode %geom_main OutputTriangleStrip\n"
 							"OpExecutionMode %geom_main OutputVertices 3\n";
 	}