I suspect this is JSR 292 related.

See the failure of
    lang/EXPR/expr751/expr75101m5/expr75101m5

in the tl langtools nightly test run here:
   http://aurora-ds.russia.sun.com:13000/functional/faces/RunsCompare.xhtml?names=11228.JDK8-LANGTOOLS-NIGHTLY-1

Note that this was run with:
   java version "1.8.0-ea"
   Java(TM) SE Runtime Environment (build 1.8.0-ea-b9220)
   Java HotSpot(TM) 64-Bit Server VM (build 22.0-b01, mixed mode)

This test passed in the previous nightly run, with HS 21.0b14 (and with the current promoted JDK 8 build) ie, there are no failures shown here:
    http://aurora-ds.russia.sun.com:13000/functional/faces/RunsCompare.xhtml?names=10890.JDK8-LANGTOOLS-NIGHTLY-1

(but note that there are failures on solaris-sparc in that nightly run)


The failure mode with HS22.0-b01 is:

Unexpected exception for the call: String inv5 = (String) handle.invoke(new Object(), (byte) 0) /*ClassCastException*/
java.lang.InternalError: unexpected code 1798266144: required class java.lang.String but encountered class java.lang.Object
at java.lang.invoke.MethodHandleNatives.raiseException(MethodHandleNatives.java:375)
at javasoft.sqe.tests.lang.expr751.expr75101m5.expr75101m5.run(expr75101m5.java:213)
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:473)
at com.sun.jck.lib.ExecJCKTestSameJVMCmd$SimpleTest.run(ExecJCKTestSameJVMCmd.java:353)
at com.sun.jck.lib.ExecJCKTestSameJVMCmd.execute(ExecJCKTestSameJVMCmd.java:260)
at com.sun.jck.lib.ExecJCKTestSameJVMCmd.run(ExecJCKTestSameJVMCmd.java:162)
at com.sun.javatest.agent.Agent$Task.executeCommand(Agent.java:815)
at com.sun.javatest.agent.Agent$Task.execute(Agent.java:759)
at com.sun.javatest.agent.Agent$Task.handleRequest(Agent.java:621)
at com.sun.javatest.agent.Agent.handleRequestsUntilClosed(Agent.java:392)
at com.sun.javatest.agent.Agent.access$000(Agent.java:60)
at com.sun.javatest.agent.Agent$1.run(Agent.java:270)
at java.lang.Thread.run(Thread.java:722)
Unexpected exception for the call: String inv6 = (String) handle.invoke((Object) 1, (byte) 2) /*ClassCastException*/
java.lang.InternalError: unexpected code 1798266144: required class java.lang.String but encountered class java.lang.Integer
at java.lang.invoke.MethodHandleNatives.raiseException(MethodHandleNatives.java:375)
at javasoft.sqe.tests.lang.expr751.expr75101m5.expr75101m5.run(expr75101m5.java:226)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:473)
at com.sun.jck.lib.ExecJCKTestSameJVMCmd$SimpleTest.run(ExecJCKTestSameJVMCmd.java:353)
at com.sun.jck.lib.ExecJCKTestSameJVMCmd.execute(ExecJCKTestSameJVMCmd.java:260)
at com.sun.jck.lib.ExecJCKTestSameJVMCmd.run(ExecJCKTestSameJVMCmd.java:162)
at com.sun.javatest.agent.Agent$Task.executeCommand(Agent.java:815)
at com.sun.javatest.agent.Agent$Task.execute(Agent.java:759)
at com.sun.javatest.agent.Agent$Task.handleRequest(Agent.java:621)
at com.sun.javatest.agent.Agent.handleRequestsUntilClosed(Agent.java:392)
at com.sun.javatest.agent.Agent.access$000(Agent.java:60)
at com.sun.javatest.agent.Agent$1.run(Agent.java:270)
at java.lang.Thread.run(Thread.java:722)
Unexpected exception for the call: String inv7 = (String) handle.invoke((Integer) 1, (byte) 2) /*ClassCastException*/
java.lang.InternalError: unexpected code 1798266144: required class java.lang.String but encountered class java.lang.Integer
at java.lang.invoke.MethodHandleNatives.raiseException(MethodHandleNatives.java:375)
at javasoft.sqe.tests.lang.expr751.expr75101m5.expr75101m5.run(expr75101m5.java:239)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:473)
at com.sun.jck.lib.ExecJCKTestSameJVMCmd$SimpleTest.run(ExecJCKTestSameJVMCmd.java:353)
at com.sun.jck.lib.ExecJCKTestSameJVMCmd.execute(ExecJCKTestSameJVMCmd.java:260)
at com.sun.jck.lib.ExecJCKTestSameJVMCmd.run(ExecJCKTestSameJVMCmd.java:162)
at com.sun.javatest.agent.Agent$Task.executeCommand(Agent.java:815)
at com.sun.javatest.agent.Agent$Task.execute(Agent.java:759)
at com.sun.javatest.agent.Agent$Task.handleRequest(Agent.java:621)
at com.sun.javatest.agent.Agent.handleRequestsUntilClosed(Agent.java:392)
at com.sun.javatest.agent.Agent.access$000(Agent.java:60)
at com.sun.javatest.agent.Agent$1.run(Agent.java:270)
at java.lang.Thread.run(Thread.java:722)