[6.0][Test] Remove class_getImageName-static test.

This test checks the behavior of class_getImageName before the runtime's hook is installed with objc_setHook_getImageName. Foundation now triggers installation of that hook very early, causing the test to fail. Reliably avoiding this is difficult, and the test is redundant with the ObjC runtime's tests, so just remove it.

rdar://132478164
(cherry picked from commit c048672)

Author: mikeash