[csa] add utilities for printf-style debugging

src/code-stub-assembler.cc

Index: src/code-stub-assembler.cc
diff --git a/src/code-stub-assembler.cc b/src/code-stub-assembler.cc
index fc73d66c1b89945239913e51b0d3c68bf40f22b5..d09d105e2bcac733bc3d73472bf0ad95637d19f3 100644
--- a/src/code-stub-assembler.cc
+++ b/src/code-stub-assembler.cc
@@ -8398,5 +8398,29 @@ Node* CodeStubAssembler::AllocatePromiseReactionJobInfo(
   return result;
 }
 
+void CodeStubAssembler::Print(const char* s) {
+#ifdef DEBUG
+  std::string formatted(s);
+  formatted += "\n";
+  Handle<String> string = isolate()->factory()->NewStringFromAsciiChecked(
+      formatted.c_str(), TENURED);
+  CallRuntime(Runtime::kGlobalPrint, NoContextConstant(), HeapConstant(string));
+#endif
+}
+
+void CodeStubAssembler::Print(const char* prefix, Node* tagged_value) {
+#ifdef DEBUG
+  if (prefix != nullptr) {
+    std::string formatted(prefix);
+    formatted += ": ";
+    Handle<String> string = isolate()->factory()->NewStringFromAsciiChecked(
+        formatted.c_str(), TENURED);
+    CallRuntime(Runtime::kGlobalPrint, NoContextConstant(),
+                HeapConstant(string));
+  }
+  CallRuntime(Runtime::kGlobalPrint, NoContextConstant(), tagged_value);

[caitp, 2017/01/24 13:30:37]

Is there any way to assert that the value outputs from the `tagged_value` node
have a tagged representation during graph generation?

+#endif
+}
+
 }  // namespace internal
 }  // namespace v8