Compiler: GBC fix, CFG dump enhancements

Repaired some GBC generation bit rot, fixed a syntax error in
.dot cfg file generation, enhanced cfg generation to work before
SSA renaming and added new cfg dump points.

Change-Id: Id73b479209ea4d963810f67bde0ed502ed7361d3
diff --git a/src/compiler/codegen/gen_loadstore.cc b/src/compiler/codegen/gen_loadstore.cc
index eec74af..6c16d40 100644
--- a/src/compiler/codegen/gen_loadstore.cc
+++ b/src/compiler/codegen/gen_loadstore.cc
@@ -46,15 +46,18 @@
     int pmap_index = SRegToPMap(cu, rl_dest.s_reg_low);
     if (cu->promotion_map[pmap_index].fp_location == kLocPhysReg) {
       // Now, determine if this vreg is ever used as a reference.  If not, we're done.
-      bool used_as_reference = false;
-      int base_vreg = SRegToVReg(cu, rl_dest.s_reg_low);
-      for (int i = 0; !used_as_reference && (i < cu->num_ssa_regs); i++) {
-        if (SRegToVReg(cu, cu->reg_location[i].s_reg_low) == base_vreg) {
-          used_as_reference |= cu->reg_location[i].ref;
+      if (!cu->gen_bitcode) {
+        // TUNING: We no longer have this info for QuickGBC - assume the worst
+        bool used_as_reference = false;
+        int base_vreg = SRegToVReg(cu, rl_dest.s_reg_low);
+        for (int i = 0; !used_as_reference && (i < cu->num_ssa_regs); i++) {
+          if (SRegToVReg(cu, cu->reg_location[i].s_reg_low) == base_vreg) {
+            used_as_reference |= cu->reg_location[i].ref;
+          }
         }
-      }
-      if (!used_as_reference) {
-        return;
+        if (!used_as_reference) {
+          return;
+        }
       }
       if (cu->promotion_map[pmap_index].core_location == kLocPhysReg) {
         // Promoted - just copy in a zero