opengles emulator: fix eglGetProcAddress

eglGetProcAddress should return a function pointer that does not
depends on the current bounded context (if any), when the user
calls one of the function pointers returned from eglGetProcAddress
for one of the GLES extension functions, the GLESv1 or GLESv2
version of the extension function shold be called depending on
the current bounded context.

For this we have added a ClientAPI (GLES) extension dispatch
table in the EGL level which points to static functions in libEGL
where each function checks in runtime the current bound context and
calls down to the GLES_CM -or- GLESv2 library function.
See ClientAPIExts.cpp, when new GLES extension functions are added
to GLESv1 or GLESv2 its definition should be added to
ClientAPIExts.in as well.

This fixes the segfault in egl_image conformance test.

Change-Id: I8464d87c2fcbe57d67bd8b891b695a690dec89f3
7 files changed