mesa: Enable GL_MESA_pack_invert unconditionally

This newly enables the extension for r100 and vieux. As far as I can
tell, that's safe to do. vieux's ReadPixels is just _mesa_readpixels,
which clearly already handles it correctly because the extension is
enabled for classic swrast. r100 has some custom acceleration paths
before falling down to _mesa_readpixels, which winds its way through to
r100_blit, which already has code to handle pack->Invert being set.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3156>
diff --git a/src/mesa/drivers/dri/i915/intel_extensions.c b/src/mesa/drivers/dri/i915/intel_extensions.c
index 05ac487..0745b21 100644
--- a/src/mesa/drivers/dri/i915/intel_extensions.c
+++ b/src/mesa/drivers/dri/i915/intel_extensions.c
@@ -70,7 +70,6 @@
    ctx->Extensions.EXT_texture_env_dot3 = true;
    ctx->Extensions.EXT_texture_filter_anisotropic = true;
    ctx->Extensions.APPLE_object_purgeable = true;
-   ctx->Extensions.MESA_pack_invert = true;
    ctx->Extensions.MESA_ycbcr_texture = true;
    ctx->Extensions.NV_texture_rectangle = true;
    ctx->Extensions.TDFX_texture_compression_FXT1 = true;
diff --git a/src/mesa/drivers/dri/i965/intel_extensions.c b/src/mesa/drivers/dri/i965/intel_extensions.c
index e93e727..f78cd82 100644
--- a/src/mesa/drivers/dri/i965/intel_extensions.c
+++ b/src/mesa/drivers/dri/i965/intel_extensions.c
@@ -126,7 +126,6 @@
    ctx->Extensions.APPLE_object_purgeable = true;
    ctx->Extensions.ATI_texture_env_combine3 = true;
    ctx->Extensions.MESA_framebuffer_flip_y = true;
-   ctx->Extensions.MESA_pack_invert = true;
    ctx->Extensions.NV_conditional_render = true;
    ctx->Extensions.NV_fog_distance = true;
    ctx->Extensions.NV_primitive_restart = true;
diff --git a/src/mesa/drivers/dri/r200/r200_context.c b/src/mesa/drivers/dri/r200/r200_context.c
index 68b6e60..49aaaa2 100644
--- a/src/mesa/drivers/dri/r200/r200_context.c
+++ b/src/mesa/drivers/dri/r200/r200_context.c
@@ -351,7 +351,6 @@
    ctx->Extensions.EXT_texture_env_dot3 = true;
    ctx->Extensions.EXT_texture_filter_anisotropic = true;
    ctx->Extensions.EXT_texture_mirror_clamp = true;
-   ctx->Extensions.MESA_pack_invert = true;
    ctx->Extensions.NV_fog_distance = true;
    ctx->Extensions.NV_texture_rectangle = true;
    ctx->Extensions.OES_EGL_image = true;
diff --git a/src/mesa/main/extensions.c b/src/mesa/main/extensions.c
index 6ded1bb..d56f678 100644
--- a/src/mesa/main/extensions.c
+++ b/src/mesa/main/extensions.c
@@ -177,7 +177,6 @@
    ctx->Extensions.EXT_texture_swizzle = GL_TRUE;
    /*ctx->Extensions.EXT_transform_feedback = GL_TRUE;*/
    ctx->Extensions.EXT_vertex_array_bgra = GL_TRUE;
-   ctx->Extensions.MESA_pack_invert = GL_TRUE;
    ctx->Extensions.MESA_ycbcr_texture = GL_TRUE;
    ctx->Extensions.NV_conditional_render = GL_TRUE;
    ctx->Extensions.NV_point_sprite = GL_TRUE;
diff --git a/src/mesa/main/extensions_table.h b/src/mesa/main/extensions_table.h
index aa72241..f7238c1 100644
--- a/src/mesa/main/extensions_table.h
+++ b/src/mesa/main/extensions_table.h
@@ -364,7 +364,7 @@
 EXT(KHR_texture_compression_astc_sliced_3d  , KHR_texture_compression_astc_sliced_3d , GLL, GLC,  x , ES2, 2015)
 
 EXT(MESA_framebuffer_flip_y                 , MESA_framebuffer_flip_y                ,  43,  43,  x ,  30, 2018)
-EXT(MESA_pack_invert                        , MESA_pack_invert                       , GLL, GLC,  x ,  x , 2002)
+EXT(MESA_pack_invert                        , dummy_true                             , GLL, GLC,  x ,  x , 2002)
 EXT(MESA_shader_integer_functions           , MESA_shader_integer_functions          , GLL, GLC,  x ,  30, 2016)
 EXT(MESA_texture_signed_rgba                , EXT_texture_snorm                      , GLL, GLC,  x ,  x , 2009)
 EXT(MESA_tile_raster_order                  , MESA_tile_raster_order                 , GLL, GLC,  x , ES2, 2017)
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index 27cc5c9..6b20334 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -4445,7 +4445,6 @@
    GLboolean KHR_texture_compression_astc_sliced_3d;
    GLboolean MESA_framebuffer_flip_y;
    GLboolean MESA_tile_raster_order;
-   GLboolean MESA_pack_invert;
    GLboolean EXT_shader_framebuffer_fetch;
    GLboolean EXT_shader_framebuffer_fetch_non_coherent;
    GLboolean MESA_shader_integer_functions;
diff --git a/src/mesa/main/pixelstore.c b/src/mesa/main/pixelstore.c
index f190c0b..d4ae7dd 100644
--- a/src/mesa/main/pixelstore.c
+++ b/src/mesa/main/pixelstore.c
@@ -94,8 +94,7 @@
          ctx->Pack.Alignment = param;
          break;
       case GL_PACK_INVERT_MESA:
-         if (!no_error &&
-             (!_mesa_is_desktop_gl(ctx) || !ctx->Extensions.MESA_pack_invert))
+         if (!no_error && !_mesa_is_desktop_gl(ctx))
             goto invalid_enum_error;
          ctx->Pack.Invert = param;
          break;
diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index 7343c47..81d3000 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -1079,7 +1079,6 @@
    extensions->ATI_texture_env_combine3 = GL_TRUE;
 
    extensions->MESA_framebuffer_flip_y = GL_TRUE;
-   extensions->MESA_pack_invert = GL_TRUE;
 
    extensions->NV_copy_image = GL_TRUE;
    extensions->NV_fog_distance = GL_TRUE;