hg: jdk/sandbox: 8215482: check for cycles in type variables can provoke NPE

[chris.hegarty at oracle.com]

Changeset: f5e601ad26a8
Author:    vromero
Date:      2019-01-14 12:24 -0500
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/f5e601ad26a8

8215482: check for cycles in type variables can provoke NPE
Reviewed-by: mcimadamore

! src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
! src/jdk.compiler/share/classes/com/sun/tools/javac/comp/MemberEnter.java
! src/jdk.compiler/share/classes/com/sun/tools/javac/comp/TypeEnter.java
+ test/langtools/tools/javac/T8215482/NPETypeVarWithOuterBoundTest.java