docs: Remove descriptions of long dead Emit* fields.

Dead since commit d8a366200 in 2010.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Acked-by: Brian Paul <brianp@vmware.com>

docs/shading.html

@@ -222,34 +222,17 @@ struct gl_shader_state
 {
    ...
    /** Driver-selectable options: */
-   GLboolean EmitHighLevelInstructions;
    GLboolean EmitCondCodes;
-   GLboolean EmitComments;
 };
 </pre>
 
 <dl>
-<dt>EmitHighLevelInstructions</dt>
-<dd>
-This option controls instruction selection for loops and conditionals.
-If the option is set high-level IF/ELSE/ENDIF, LOOP/ENDLOOP, CONT/BRK
-instructions will be emitted.
-Otherwise, those constructs will be implemented with BRA instructions.
-</dd>
-
 <dt>EmitCondCodes</dt>
 <dd>
 If set, condition codes (ala GL_NV_fragment_program) will be used for
 branching and looping.
 Otherwise, ordinary registers will be used (the IF instruction will
 examine the first operand's X component and do the if-part if non-zero).
-This option is only relevant if EmitHighLevelInstructions is set.
-</dd>
-
-<dt>EmitComments</dt>
-<dd>
-If set, instructions will be annotated with comments to help with debugging.
-Extra NOP instructions will also be inserted.
 </dd>
 </dl>