hg: jdk/jdk: 8209173: javac fails with completion exception while reporting an error

[vicente.romero at oracle.com]

Changeset: 42d36db61500
Author:    vromero
Date:      2018-08-24 13:30 -0700
URL:       http://hg.openjdk.java.net/jdk/jdk/rev/42d36db61500

8209173: javac fails with completion exception while reporting an error
Reviewed-by: mcimadamore

! src/jdk.compiler/share/classes/com/sun/tools/javac/util/RichDiagnosticFormatter.java
+ test/langtools/tools/javac/T8209173/CodeCompletionExceptTest.java