Convert Linkage to use MachineSignature.

src/compiler/structured-machine-assembler.cc

Index: src/compiler/structured-machine-assembler.cc
diff --git a/src/compiler/structured-machine-assembler.cc b/src/compiler/structured-machine-assembler.cc
index 56da5fb1af21a04fe8f15191a1b6d5772e22f69f..99c7c3821ddf71f8a32ce941bece3d2b52907a07 100644
--- a/src/compiler/structured-machine-assembler.cc
+++ b/src/compiler/structured-machine-assembler.cc
@@ -17,13 +17,14 @@ void Variable::Set(Node* value) const { smasm_->SetVariable(offset_, value); }
 
 
 StructuredMachineAssembler::StructuredMachineAssembler(
-    Graph* graph, MachineCallDescriptorBuilder* call_descriptor_builder,
-    MachineType word)
+    Graph* graph, MachineSignature* machine_sig, MachineType word)
     : GraphBuilder(graph),
       schedule_(new (zone()) Schedule(zone())),
       machine_(zone(), word),
       common_(zone()),
-      call_descriptor_builder_(call_descriptor_builder),
+      machine_sig_(machine_sig),
+      call_descriptor_(
+          Linkage::GetSimplifiedCDescriptor(graph->zone(), machine_sig)),
       parameters_(NULL),
       current_environment_(new (zone())
                            Environment(zone(), schedule()->start(), false)),