mesa: Release gl_debug_state when destroying context.

Commit 6e8d04a caused a leak by allocating ctx->Debug but never freeing it.
Release the memory in _mesa_free_errors_data when destroying a context.
Use FREE to match CALLOC_STRUCT from _mesa_get_debug_state.

Reviewed-by: Brian Paul <brianp@vmware.com>
docs: Import 10.0.4 release notes, add news item.
glsl: Rewrite unrolled link_invalidate_variable_locations calls as a loop

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
glsl: Fix typo

Remove extra "any" and re-word-wrap the comment.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Use the magic behaviour of GL_BACK in GLES 1 and 2 as well as 3

In GLES 3 it is not possible to select rendering to the front buffer and
instead selecting GL_BACK has the magic interpretation that it is either the
front buffer on single-buffered configs or the back buffer on double-buffered.
GLES 1 and 2 have no way of selecting the draw buffer at all. In that case we
were initialising the draw buffer to either GL_FRONT or GL_BACK depending on
the context's config and then leaving it at that.

When we switch to having configless contexts we ideally want Mesa to
automatically switch between the front and back buffer whenever a double-
or single-buffered surface is bound. To make this happen we can just allow
the magic behaviour from GLES 3 in GLES 1 and 2 as well. It shouldn't matter
what the internal value of the draw buffer is in GLES 1 and 2 because there
is no way to query it from the external API.

Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
Fix the initial value of glDrawBuffers for GLES

Under GLES 3 it is not valid to pass GL_FRONT to glDrawBuffers. Instead,
GL_BACK has a magic interpretation which means it will render to the front
buffer on single-buffered contexts and the back buffer on double-buffered. We
were incorrectly setting the initial value to GL_FRONT for single-buffered
contexts. This probably doesn't really matter at the moment except that
presumably it would be exposed in the API via glGetIntegerv.

When we switch to configless contexts this is more important because in that
case we always want to rely on the magic interpretation of GL_BACK in order to
automatically switch between the front and back buffer when a new surface with
a different number of buffers is bound. We also do this for GLES 1 and 2
because the internal value doesn't matter in that case and it is convenient to
use the same code to have the magic interpretation of GL_BACK.

Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
eglCreateContext: Remove the check for whether config == 0

In eglCreateContext there is a check for whether the config parameter is zero
and in this case it will avoid reporting an error if the
EGL_KHR_surfacless_context extension is supported. However there is nothing in
that extension which says you can create a context without a config and Mesa
breaks if you try this so it is probably better to leave it reporting an
error.

The original check was added in b90a3e7d8b1bc based on the API-specific
extensions EGL_KHR_surfaceless_opengl/gles1/gles2. This was later changed to
refer to EGL_KHR_surfacless_context in b50703aea5. Perhaps the original
extensions specified a configless context but the new one does not.

Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
Add the EGL_MESA_configless_context extension

This extension provides a way for an application to render to multiple
surfaces with different buffer formats without having to use multiple
contexts. An EGLContext can be created without an EGLConfig by passing
EGL_NO_CONFIG_MESA. In that case there are no restrictions on the surfaces
that can be used with the context apart from that they must be using the same
EGLDisplay.

_mesa_initialze_context can now take a NULL gl_config which will mark the
context as ‘configless’. It will memset the visual to zero in that case.
Previously the i965 and i915 drivers were explicitly creating a zeroed visual
whenever 0 is passed for the EGLConfig. Mesa needs to be aware that the
context is configless because it affects the initial value to use for
glDrawBuffer. The first time the context is bound it will set the initial
value for configless contexts depending on whether the framebuffer used is
double-buffered.

Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>