test: Add 4 tests using EGL and OpenGLESv2

test: Add 4 tests using EGL and OpenGLESv2

These are similar variants to the four existing tests using EGL and OpenGL.

To add these tests we add a new configure-time check to find the
compilation flags for GLESv2. We also drop the set_2d_projection code
which was using glLoadIdentity, glMatrixMode, and glOrtho functions
which apparently don't exist in GLESv2. So common.s and all tests with
custom wrappers are modified to drop these calls.

As with the egl-opengl tests, all new tests except for the dlsym-based
test pass. That's not too surprising since there are so many twisty
paths in trying to get all the dlopen/dlsym stuff to work correctly.

And hurrah for test suites finding bugs!