[dyj] in codegen, add Drell Yan gg_eegguu

This is the most complex subprocess from nobm_pp_eejjjj (there are 856 Feynman diagrams).
I checked that there is no need to use the nobmass model, it gives essentially the same code (as far as complexity is concerned).
Code generation takes half a minute including additional checks.

Author: valassi

epochX/cudacpp/CODEGEN/generateAndCompare.sh

@@ -115,6 +115,15 @@ function codeGenAndDiff()
       define j = p
       generate p p > e+ e- j j j j @4"
       ;;
+    gg_eegguu)
+      cmd="generate g g > e+ e- g g u u~"
+      ;;
+    #nobm_gg_eegguu) # essentially the same code as gg_eegguu
+    #  cmd="import model sm-no_b_mass
+    #  define p = p b b~
+    #  define j = p
+    #  generate g g > e+ e- g g u u~"
+    #  ;;
     loop_nobm_gg_tt)
       cmd="import model loop_sm-no_b_mass
       generate g g > t t~"