deps: cherry-pick f5fad6d from upstream v8

Original commit message:

    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}

PR-URL: https://github.com/nodejs/node/pull/12826
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

deps/v8/include/v8-version.h

@@ -11,7 +11,7 @@
 #define V8_MAJOR_VERSION 5
 #define V8_MINOR_VERSION 8
 #define V8_BUILD_NUMBER 283
-#define V8_PATCH_LEVEL 38
+#define V8_PATCH_LEVEL 39
 
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)

deps/v8/include/v8.h

@@ -7982,6 +7982,11 @@ 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

deps/v8/src/api.cc

@@ -2691,6 +2691,10 @@ 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;