Swallow exceptions while setting __gwt$exception Bug: issue 8449 Change-Id: I63e8321d1a68b1d20a8a4c3e86b4051320abc034 Review-Link: https://gwt-review.googlesource.com/#/c/5506/ (cherry picked from commit 4f1357c7349f0d755529a8ad228d67dac7ac9165)