Following 17 tests have been failing(almost consistently) in JDK8 tl nightly runs since 09/25:
tools/javac/6917288/GraphicalInstallerTest.java
tools/javac/7144981/IgnoreIgnorableCharactersInInput.java
tools/javac/T6999210.java
tools/javac/T8022162/IncorrectSignatureDeterminationForInnerClassesTest.java

tools/javac/api/T6838467.java
tools/javac/api/T6877206.java
tools/javac/classreader/T7031108.java
tools/javac/fatalErrors/NoJavaLangTest.java
tools/javac/links/LinksTest.java
tools/javac/nativeHeaders/javahComparison/CompareTest.java
tools/javac/policy/test1/Test1b.java
tools/javac/policy/test1/Test1b.java#id1
tools/javac/policy/test1/Test1b.java#id2
tools/javac/policy/test1/Test1b.java#id3
tools/javac/processing/model/type/BasicAnnoTests.java
tools/javadoc/6964914/Test.java

The tests mostly fail on Win32/Win64 platforms. It does not look like a machine issue as the tests have been run on different machines.

Each of the jtr files for the above tests have the below common stacktrace:
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at com.sun.javatest.regtest.MainAction$SameVMRunnable.run(MainAction.java:728)
at java.lang.Thread.run(Thread.java:724)

Aurora job: http://aurora.ru.oracle.com/functional/faces/RunDetails.xhtml?names=302719.JDK8-LANGTOOLS-NIGHTLY-4

It may be that test files are not getting cleaned up once the test is getting completed.