Expand C++ macros in tools/generate-runtime-tests.py to increase coverage

test/mjsunit/runtime-gen/dataviewsetfloat64.js

Index: test/mjsunit/runtime-gen/dataviewsetfloat64.js
diff --git a/test/mjsunit/runtime-gen/numbertoradixstring.js b/test/mjsunit/runtime-gen/dataviewsetfloat64.js
similarity index 53%
copy from test/mjsunit/runtime-gen/numbertoradixstring.js
copy to test/mjsunit/runtime-gen/dataviewsetfloat64.js
index 6a90cd904c40f5e59f3170ef471f6c2a8e840760..97c5d3eae1f3aa52570b8a419f055d66a7ca42d4 100644
--- a/test/mjsunit/runtime-gen/numbertoradixstring.js
+++ b/test/mjsunit/runtime-gen/dataviewsetfloat64.js
@@ -1,6 +1,8 @@
 // Copyright 2014 the V8 project authors. All rights reserved.
 // AUTO-GENERATED BY tools/generate-runtime-tests.py, DO NOT MODIFY
 // Flags: --allow-natives-syntax --harmony
+var _holder = new DataView(new ArrayBuffer(24));
+var _offset = 1.5;
 var _value = 1.5;
-var arg1 = 2;
-%NumberToRadixString(_value, arg1);
+var _is_little_endian = true;
+%DataViewSetFloat64(_holder, _offset, _value, _is_little_endian);