assert(_exits.control()->is_top() || !_gvn.type(ret_phi)->empty()) failed: return value must be well defined

Test failed in nightlies:

;; Using jvm: "/export/local/aurora/sandbox/sca/vmsqe/jdk/nightly/fastdebug/comp_baseline/linux-i586/jre/lib/i386/server/libjvm.so"
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/opt/jprt/T/P1/192921.vkozlov/s/src/share/vm/opto/parse1.cpp:989), pid=18485, tid=3843935088
# assert(_exits.control()->is_top() || !_gvn.type(ret_phi)->empty()) failed: return value must be well defined
#
# JRE version: Java(TM) SE Runtime Environment (9.0-b26) (build 1.9.0-ea-fastdebug-b26)
# Java VM: Java HotSpot(TM) Server VM (1.9.0-fastdebug-internal-201408151929.vkozlov.main_to_comp compiled mode linux-x86 )
# Core dump written. Default location: /export/local/aurora/sandbox/results/client/9/core or core.18485
#
# If you would like to submit a bug report, please visit:
# http://bugreport.sun.com/bugreport/crash.jsp
#

--------------- T H R E A D ---------------

Current thread (0xe559c800): JavaThread "C2 CompilerThread0" daemon [_thread_in_native, id=18505, stack(0xe515c000,0xe51dd000)]

Stack: [0xe515c000,0xe51dd000], sp=0xe51dafa0, free space=507k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x1066c08] VMError::report_and_die()+0x198;; VMError::report_and_die()+0x198
V [libjvm.so+0x6dc8d6] report_vm_error(char const*, int, char const*, char const*)+0x76;; report_vm_error(char const*, int, char const*, char const*)+0x76
V [libjvm.so+0xde6ee7] Parse::do_exits()+0xad7;; Parse::do_exits()+0xad7
V [libjvm.so+0xdf0d98] Parse::Parse(JVMState*, ciMethod*, float)+0xdd8;; Parse::Parse(JVMState*, ciMethod*, float)+0xdd8
V [libjvm.so+0x513a28] ParseGenerator::generate(JVMState*)+0x158;; ParseGenerator::generate(JVMState*)+0x158
V [libjvm.so+0x653dc2] Compile::Compile(ciEnv*, C2Compiler*, ciMethod*, int, bool, bool, bool)+0x1362;; Compile::Compile(ciEnv*, C2Compiler*, ciMethod*, int, bool, bool, bool)+0x1362
V [libjvm.so+0x5123b7] C2Compiler::compile_method(ciEnv*, ciMethod*, int)+0x327;; C2Compiler::compile_method(ciEnv*, ciMethod*, int)+0x327
V [libjvm.so+0x661d59] CompileBroker::invoke_compiler_on_method(CompileTask*)+0x629;; CompileBroker::invoke_compiler_on_method(CompileTask*)+0x629
V [libjvm.so+0x6637b0] CompileBroker::compiler_thread_loop()+0x550;; CompileBroker::compiler_thread_loop()+0x550
V [libjvm.so+0xfc43f5] compiler_thread_entry(JavaThread*, Thread*)+0x55;; compiler_thread_entry(JavaThread*, Thread*)+0x55
V [libjvm.so+0xfd85d9] JavaThread::thread_main_inner()+0x299;; JavaThread::thread_main_inner()+0x299
V [libjvm.so+0xfd89e6] JavaThread::run()+0x296;; JavaThread::run()+0x296
V [libjvm.so+0xd99810] java_start(Thread*)+0x100;; java_start(Thread*)+0x100
C [libpthread.so.0+0x6a49]
C [libc.so.6+0xdee1e] clone+0x5e


Current CompileTask:
C2: 32761 5460 b sun.nio.cs.ISO_8859_1::newEncoder (10 bytes)