Changed the constructor of BufferedRawMachineAssemblerTester.

This change does not change how the BufferedRawMachineAssemblerTester is
used in tests, but it makes its construction in other constructors (e.g.
in the WasmRunner) cleaner.

R=titzer@chromium.org

Review URL: https://codereview.chromium.org/1414203009

Cr-Commit-Position: refs/heads/master@{#31850}

test/cctest/compiler/codegen-tester.h

@@ -77,28 +77,12 @@ template <typename ReturnType>
 class BufferedRawMachineAssemblerTester
     : public RawMachineAssemblerTester<int32_t> {
  public:
-  BufferedRawMachineAssemblerTester()
-      : BufferedRawMachineAssemblerTester(0, kMachNone, kMachNone, kMachNone,
-                                          kMachNone) {}
-
-
-  explicit BufferedRawMachineAssemblerTester(MachineType p0)
-      : BufferedRawMachineAssemblerTester(1, p0, kMachNone, kMachNone,
-                                          kMachNone) {}
-
-
-  BufferedRawMachineAssemblerTester(MachineType p0, MachineType p1)
-      : BufferedRawMachineAssemblerTester(2, p0, p1, kMachNone, kMachNone) {}
-
-
-  BufferedRawMachineAssemblerTester(MachineType p0, MachineType p1,
-                                    MachineType p2)
-      : BufferedRawMachineAssemblerTester(3, p0, p1, p2, kMachNone) {}
-
-
-  BufferedRawMachineAssemblerTester(MachineType p0, MachineType p1,
-                                    MachineType p2, MachineType p3)
-      : BufferedRawMachineAssemblerTester(4, p0, p1, p2, p3) {}
+  BufferedRawMachineAssemblerTester(MachineType p0 = kMachNone,
+                                    MachineType p1 = kMachNone,
+                                    MachineType p2 = kMachNone,
+                                    MachineType p3 = kMachNone)
+      : BufferedRawMachineAssemblerTester(ComputeParameterCount(p0, p1, p2, p3),
+                                          p0, p1, p2, p3) {}
 
 
   // The BufferedRawMachineAssemblerTester does not pass parameters directly
@@ -193,6 +177,24 @@ class BufferedRawMachineAssemblerTester
   }
 
 
+  static uint32_t ComputeParameterCount(MachineType p0, MachineType p1,
+                                        MachineType p2, MachineType p3) {
+    if (p0 == kMachNone) {
+      return 0;
+    }
+    if (p1 == kMachNone) {
+      return 1;
+    }
+    if (p2 == kMachNone) {
+      return 2;
+    }
+    if (p3 == kMachNone) {
+      return 3;
+    }
+    return 4;
+  }
+
+
   CSignature* test_graph_signature_;
   Node* parameter_nodes_[4];
   uint32_t return_parameter_index_;