Add js engine information in React Native error reporting

Summary:
To avoid "js engine: ..." appearing everywhere, only add this information
to the error message when react native is reporting errors to the server.

Reviewed By: yungsters

Differential Revision: D9754371

fbshipit-source-id: a8001480c75ccf93c953c79f26470df678871cb3

Libraries/Core/Devtools/parseErrorStack.js

@@ -19,6 +19,7 @@ export type StackFrame = {
 
 export type ExtendedError = Error & {
   framesToPop?: number,
+  jsEngine?: string,
 };
 
 function parseErrorStack(e: ExtendedError): Array<StackFrame> {

Libraries/Core/ExceptionsManager.js

@@ -22,18 +22,16 @@ function reportException(e: ExtendedError, isFatal: boolean) {
     const parseErrorStack = require('parseErrorStack');
     const stack = parseErrorStack(e);
     const currentExceptionID = ++exceptionID;
+    const message =
+      e.jsEngine == null ? e.message : `${e.message}, js engine: ${e.jsEngine}`;
     if (isFatal) {
       ExceptionsManager.reportFatalException(
-        e.message,
+        message,
         stack,
         currentExceptionID,
       );
     } else {
-      ExceptionsManager.reportSoftException(
-        e.message,
-        stack,
-        currentExceptionID,
-      );
+      ExceptionsManager.reportSoftException(message, stack, currentExceptionID);
     }
     if (__DEV__) {
       const symbolicateStackTrace = require('symbolicateStackTrace');