[VM DBC compiler and simulator] Support reified generic functions.

runtime/vm/flow_graph_allocator.cc

Index: runtime/vm/flow_graph_allocator.cc
diff --git a/runtime/vm/flow_graph_allocator.cc b/runtime/vm/flow_graph_allocator.cc
index e70a5b781eec4f1a248a02ceca48921dbac1fdbe..e3e0e4b188ae404d4dfa3fa3394ca4dc94bd5fe0 100644
--- a/runtime/vm/flow_graph_allocator.cc
+++ b/runtime/vm/flow_graph_allocator.cc
@@ -703,11 +703,19 @@ void FlowGraphAllocator::ProcessInitialDefinition(Definition* defn,
   } else if (defn->IsSpecialParameter()) {
     SpecialParameterInstr* param = defn->AsSpecialParameter();
     if (param->kind() == SpecialParameterInstr::kContext) {
-#if !defined(TARGET_ARCH_DBC)
-      const Register context_reg = CTX;
+#if defined(TARGET_ARCH_DBC)
+      intptr_t context_reg = flow_graph_.num_copied_params();
+      ASSERT(-flow_graph_.parsed_function().first_stack_local_index() - 1 ==
+             context_reg);
+      if (flow_graph_.parsed_function().function_type_arguments() != NULL) {
+        // The first slot is used for function type arguments, either as their
+        // permanent location or as their temporary location when captured.
+        // So use the next one for the context.
+        context_reg++;
+      }
 #else
-      const intptr_t context_reg = flow_graph_.num_copied_params();
-#endif
+      const Register context_reg = CTX;
+#endif  // defined(TARGET_ARCH_DBC)
 
       AssignSafepoints(defn, range);
       range->finger()->Initialize(range);
@@ -721,11 +729,15 @@ void FlowGraphAllocator::ProcessInitialDefinition(Definition* defn,
     }
     ASSERT(param->kind() == SpecialParameterInstr::kTypeArgs);
 #if defined(TARGET_ARCH_DBC)
-    UNIMPLEMENTED();
-#endif
+    const intptr_t slot_index = flow_graph_.num_copied_params();
+    ASSERT(-flow_graph_.parsed_function().first_stack_local_index() - 1 ==
+           slot_index);
+    range->set_assigned_location(Location::RegisterLocation(slot_index));
+#else
     const intptr_t slot_index = flow_graph_.num_copied_params();
     range->set_assigned_location(Location::StackSlot(slot_index, FPREG));
     range->set_spill_slot(Location::StackSlot(slot_index, FPREG));
+#endif  // defined(TARGET_ARCH_DBC)
   } else {
     ConstantInstr* constant = defn->AsConstant();
     ASSERT(constant != NULL);