Use tcc and the emitted C code from s_fragprog_to_c.c to dynamically compile

and execute fragment programs.  Very limited and experimental, but works
well enough to run arbfplight.c.

	http://fabrice.bellard.free.fr/tcc/

Compile with 'make linux-tcc', being sure to make clean first.

src/mesa/swrast/s_nvfragprog.c

@@ -1357,10 +1357,18 @@ _swrast_exec_fragment_program( GLcontext *ctx, struct sw_span *span )
          init_machine(ctx, &ctx->FragmentProgram.Machine,
                       ctx->FragmentProgram.Current, span, i);
 
+#ifdef USE_TCC
+         if (!_swrast_execute_codegen_program(ctx, program, ~0,
+					      &ctx->FragmentProgram.Machine,
+					      span, i)) {
+            span->array->mask[i] = GL_FALSE;  /* killed fragment */
+         }
+#else
          if (!execute_program(ctx, program, ~0,
                               &ctx->FragmentProgram.Machine, span, i)) {
             span->array->mask[i] = GL_FALSE;  /* killed fragment */
          }
+#endif
 
          /* Store output registers */
          {