Native bindings to the KHR_cl_event2 extension.

This extension allows creating an EGL sync object linked to an OpenCL event object, potentially improving efficiency of sharing images between the two APIs. The companion cl_khr_egl_event extension provides the complementary functionality of creating an OpenCL event object from an EGL sync object.

This extension is functionally identical to EGL_KHR_cl_event, but is intended to replace that extension. It exists only to address an implementation issue on 64-bit platforms where passing OpenCL event handles in an EGLint attribute list value is impossible, because the implementations use a 32-bit type for EGLint.

This extension also incorporates some required functionality from the EGL_KHR_fence_sync extension, similarly modified for 64-bit platforms.

Requires EGL 1.4 and KHR_fence_sync.