From FreeBSD
include same flags for OpenBSD

Index: CMakeLists.txt
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -35,7 +35,7 @@ if(X11_FOUND)
 	add_definitions(-DPIGLIT_HAS_X11)
 endif()
 
-if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
+if(CMAKE_SYSTEM_NAME STREQUAL "Linux" OR ${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
 	set(PIGLIT_BUILD_GLES_TESTS_DEFAULT ON)
 else()
 	set(PIGLIT_BUILD_GLES_TESTS_DEFAULT OFF)
@@ -51,7 +51,7 @@ if(PIGLIT_BUILD_GL_TESTS)
 	find_package(OpenGL REQUIRED)
 endif()
 
-if(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
+if(${CMAKE_SYSTEM_NAME} MATCHES "Linux" OR ${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
 	option(PIGLIT_USE_WAFFLE "Use Waffle in place of GLUT" ON)
 else()
 	option(PIGLIT_USE_WAFFLE "Use Waffle in place of GLUT" OFF)
@@ -130,7 +130,7 @@ if(PIGLIT_BUILD_CL_TESTS)
 	find_package(OpenCL 1.2 REQUIRED)
 endif(PIGLIT_BUILD_CL_TESTS)
 
-IF(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
+IF(${CMAKE_SYSTEM_NAME} MATCHES "Linux" OR ${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
 	if(X11_FOUND AND OPENGL_gl_LIBRARY)
 		# Assume the system has GLX. In the future, systems may exist
 		# with libGL and libX11 but no GLX, but that world hasn't
@@ -150,7 +150,7 @@ IF(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
 		endif()
 	endif(GBM_FOUND)
 
-	pkg_check_modules(WAYLAND QUIET wayland-client)
+	#pkg_check_modules(WAYLAND QUIET wayland-client)
 	if (WAYLAND_FOUND)
 		set(PIGLIT_HAS_WAYLAND True)
 		add_definitions(-DPIGLIT_HAS_WAYLAND)
@@ -169,6 +169,11 @@ IF(${CMAKE_SYSTEM_NAME} MATCHES "Linux")
 	pkg_check_modules(XCB_DRI2 QUIET xcb-dri2)
 	pkg_check_modules(GLPROTO QUIET glproto)
 	pkg_check_modules(LIBVULKAN QUIET vulkan)
+
+	if (LIBVULKAN_FOUND)
+		include_directories(${LIBVULKAN_INCLUDE_DIRS})
+	endif()
+
 ELSEIF(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 	if (PIGLIT_USE_WAFFLE)
 		set(PIGLIT_HAS_WGL True)
@@ -380,7 +385,7 @@ endif()
 
 check_c_source_compiles(
 	"
-	#define _POSIX_C_SOURCE 199309L
+	#define _POSIX_C_SOURCE 200112L
 	#include <time.h>
 	int main() { return clock_gettime(CLOCK_MONOTONIC, NULL); }
 	"
@@ -424,7 +429,7 @@ if(HAVE_LIBCACA)
 endif(HAVE_LIBCACA)
 endif(GBM_FOUND)
 
-if(PIGLIT_USE_WAFFLE AND ${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
+if(PIGLIT_USE_WAFFLE AND ${CMAKE_SYSTEM_NAME} STREQUAL "Linux" OR ${CMAKE_SYSTEM_NAME} MATCHES "OpenBSD")
 	pkg_check_modules(EGL egl)
 endif()