[turbofan] Clean up cctest "framework" for dealing with native calls.

src/compiler/raw-machine-assembler.h

Index: src/compiler/raw-machine-assembler.h
diff --git a/src/compiler/raw-machine-assembler.h b/src/compiler/raw-machine-assembler.h
index b33836802489dcdb7639fb79ccb31063c41845de..8e3871f672c70003276e0e0df7624aa64851e733 100644
--- a/src/compiler/raw-machine-assembler.h
+++ b/src/compiler/raw-machine-assembler.h
@@ -302,15 +302,6 @@ class RawMachineAssembler : public GraphBuilder {
     return NewNode(machine()->Uint64Mod(), a, b);
   }
 
-  // TODO(turbofan): What is this used for?
-  Node* ConvertIntPtrToInt32(Node* a) {
-    return kPointerSize == 8 ? NewNode(machine()->TruncateInt64ToInt32(), a)
-                             : a;
-  }
-  Node* ConvertInt32ToIntPtr(Node* a) {
-    return kPointerSize == 8 ? NewNode(machine()->ChangeInt32ToInt64(), a) : a;
-  }
-
 #define INTPTR_BINOP(prefix, name)                     \
   Node* IntPtr##name(Node* a, Node* b) {               \
     return kPointerSize == 8 ? prefix##64##name(a, b)  \
@@ -454,6 +445,17 @@ class RawMachineAssembler : public GraphBuilder {
   // Parameters.
   Node* Parameter(size_t index);
 
+  // Pointer utilities.
+  Node* LoadFromPointer(void* address, MachineType rep, int32_t offset = 0) {
+    return Load(rep, PointerConstant(address), Int32Constant(offset));
+  }
+  void StoreToPointer(void* address, MachineType rep, Node* node) {
+    Store(rep, PointerConstant(address), node);
+  }
+  Node* StringConstant(const char* string) {
+    return HeapConstant(isolate()->factory()->InternalizeUtf8String(string));
+  }
+
   // Control flow.
   Label* Exit();
   void Goto(Label* label);