EGL_KHR_fence_sync: Add conformance tests

Add the following subtests:
  eglCreateSyncKHR_default_attributes
  eglCreateSyncKHR_invalid_display
  eglCreateSyncKHR_invalid_attrib_list
  eglCreateSyncKHR_wrong_display_same_thread
  eglCreateSyncKHR_with_display_bound_in_other_thread
  eglCreateSyncKHR_invalid_sync_type
  eglCreateSyncKHR_no_current_context
  eglGetSyncAttribKHR_invalid_sync
  eglGetSyncAttribKHR_invalid_attrib
  eglGetSyncAttribKHR_sync_status
  eglClientWaitSyncKHR_invalid_flag
  eglClientWaitSyncKHR_zero_timeout
  eglClientWaitSyncKHR_flag_sync_flush
  eglClientWaitSyncKHR_invalid_sync
  eglClientWaitSyncKHR_nonzero_timeout
  eglDestroySyncKHR_invalid_sync

The set of tests exhaustively cover the EGL_KHR_fence_sync spec, except
for two excerpts documented in the TODO section of the test file.

On Mesa, all tests currently skip.

I did not validate the tests against an existing implementation of
EGL_KHR_fence_sync because I have no access to one. To my knowledge,
Android and ARM ChromeOS provide EGL_KHR_fence_sync, but no desktop EGL
does (except maybe NVidia's recently released 32-bit EGL for Linux).

When an implementation arrives in Mesa, or when someone runs the tests
on ARM, we will likely discover some latent bugs in the tests.

Signed-off-by: Chad Versace <chad.versace@linux.intel.com>