ARB prog: replace 'unsigned' with 'gl_state_index'

Fixes compilation warnings with MSVC.
diff --git a/src/mesa/shader/program_parse.y b/src/mesa/shader/program_parse.y
index 2f5d303..06c1915 100644
--- a/src/mesa/shader/program_parse.y
+++ b/src/mesa/shader/program_parse.y
@@ -117,7 +117,7 @@
    unsigned attrib;
    int integer;
    float real;
-   unsigned state[5];
+   gl_state_index state[STATE_LENGTH];
    int negate;
    struct asm_vector vector;
    gl_inst_opcode opcode;
@@ -2077,8 +2077,7 @@
 
    name = _mesa_program_state_string(tokens);
    index = _mesa_add_parameter(param_list, PROGRAM_STATE_VAR, name,
-                               size, GL_NONE,
-                               NULL, (gl_state_index *) tokens, 0x0);
+                               size, GL_NONE, NULL, tokens, 0x0);
    param_list->StateFlags |= _mesa_program_state_flags(tokens);
 
    /* free name string here since we duplicated it in add_parameter() */