Expose TryCatch is_verbose_

This commit adds a getter for the private is_verbose_ member.
The use case for this comes from Node.js where the ability to avoid
calling FatalException if the TryCatch is verbose would be nice to have.

BUG=

Review-Url: https://codereview.chromium.org/2840803002
Cr-Commit-Position: refs/heads/master@{#45018}

include/v8.h

@@ -8207,6 +8207,11 @@ class V8_EXPORT TryCatch {
    */
   void SetVerbose(bool value);
 
+  /**
+   * Returns true if verbosity is enabled.
+   */
+  bool IsVerbose() const;
+
   /**
    * Set whether or not this TryCatch should capture a Message object
    * which holds source information about where the exception

src/api.cc

@@ -2711,6 +2711,10 @@ void v8::TryCatch::SetVerbose(bool value) {
   is_verbose_ = value;
 }
 
+bool v8::TryCatch::IsVerbose() const {
+  return is_verbose_;
+}
+
 
 void v8::TryCatch::SetCaptureMessage(bool value) {
   capture_message_ = value;