Revert of Use displayName in Error.stack rendering if present.

src/js/messages.js

Index: src/js/messages.js
diff --git a/src/js/messages.js b/src/js/messages.js
index db66fd38c56d87ca6190ad7957204ac469338301..feb14d378844a690de97e4d4e1d4dd323c0841b3 100644
--- a/src/js/messages.js
+++ b/src/js/messages.js
@@ -618,11 +618,6 @@
   return %CallSiteGetFunctionNameRT(this);
 }
 
-function CallSiteGetDebugName() {
-  // See if the function knows its own name
-  return %CallSiteGetDebugNameRT(this);
-}
-
 function CallSiteGetMethodName() {
   // See if we can find a unique property on the receiver that holds
   // this function.
@@ -681,13 +676,10 @@
 
   var line = "";
   var functionName = this.getFunctionName();
-  var debugName = this.getDebugName();
+  var addSuffix = true;
   var isConstructor = this.isConstructor();
   var isMethodCall = !(this.isToplevel() || isConstructor);
-  if (debugName) {
-    if (isConstructor) line += "new ";
-    line += debugName;
-  } else if (isMethodCall) {
+  if (isMethodCall) {
     var typeName = GetTypeName(GET_PRIVATE(this, callSiteReceiverSymbol), true);
     var methodName = this.getMethodName();
     if (functionName) {
@@ -708,9 +700,13 @@
   } else if (functionName) {
     line += functionName;
   } else {
-    return line + fileLocation;
-  }
-  return line + " (" + fileLocation + ")";
+    line += fileLocation;
+    addSuffix = false;
+  }
+  if (addSuffix) {
+    line += " (" + fileLocation + ")";
+  }
+  return line;
 }
 
 utils.SetUpLockedPrototype(CallSite, ["receiver", "fun", "pos"], [
@@ -722,7 +718,6 @@
   "getScriptNameOrSourceURL", CallSiteGetScriptNameOrSourceURL,
   "getFunction", CallSiteGetFunction,
   "getFunctionName", CallSiteGetFunctionName,
-  "getDebugName", CallSiteGetDebugName,
   "getMethodName", CallSiteGetMethodName,
   "getFileName", CallSiteGetFileName,
   "getLineNumber", CallSiteGetLineNumber,