mesa: add EXT_dsa indexed texture commands functions

Added functions:
  - EnableClientStateIndexedEXT
  - DisableClientStateIndexedEXT
  - EnableClientStateiEXT
  - DisableClientStateiEXT

Implemented using the idiom provided by the spec:

        if (array == TEXTURE_COORD_ARRAY) {
          int savedClientActiveTexture;

          GetIntegerv(CLIENT_ACTIVE_TEXTURE, &savedClientActiveTexture);
          ClientActiveTexture(TEXTURE0+index);
          XXX(array);
          ClientActiveTexture(savedActiveTexture);
        } else {
          // Invalid enum
        }

src/mapi/glapi/gen/EXT_direct_state_access.xml

@@ -313,6 +313,16 @@
       <param name="texture" type="GLuint" />
    </function>
 
+  <function name="EnableClientStateIndexedEXT" alias="EnableClientStateiEXT">
+      <param name="array" type="GLenum" />
+      <param name="index" type="GLuint" />
+   </function>
+
+  <function name="DisableClientStateIndexedEXT" alias="DisableClientStateiEXT">
+      <param name="array" type="GLenum" />
+      <param name="index" type="GLuint" />
+   </function>
+
    <!-- OpenGL 1.3 -->
 
    <function name="MatrixLoadTransposefEXT" offset="assign">
@@ -476,5 +486,15 @@
       <param name="pname" type="GLenum" />
       <param name="params" type="GLint *" />
    </function>
+
+   <function name="EnableClientStateiEXT">
+      <param name="array" type="GLenum" />
+      <param name="index" type="GLuint" />
+   </function>
+
+   <function name="DisableClientStateiEXT">
+      <param name="array" type="GLenum" />
+      <param name="index" type="GLuint" />
+   </function>
 </category>
 </OpenGLAPI>

src/mapi/glapi/gen/static_data.py

@@ -1514,6 +1514,8 @@ offsets = {
     "NamedFramebufferTexture3DEXT": 1478,
     "NamedFramebufferRenderbufferEXT": 1479,
     "GetNamedFramebufferAttachmentParameterivEXT": 1480,
+    "EnableClientStateiEXT": 1481,
+    "DisableClientStateiEXT": 1482,
 
 }