Segmentation fault in PhaseCFG::do_DFS

Use the attached SDD0.java to reproduce this issue.

# Internal Error (open/src/hotspot/share/opto/phaseX.cpp:1051), pid=947024, tid=947040
# assert(false) failed: modified node is not on IGVN._worklist

Current CompileTask:
C2: 1638 1124 ! 4 SDD0::m3 (555 bytes)

Stack: [0x00007f045393b000,0x00007f0453a3c000], sp=0x00007f0453a36640, free space=1005k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x18b9b94] VMError::report_and_die(int, char const*, char const*, __va_list_tag*, Thread*, unsigned char*, void*, void*, char const*, int, unsigned long)+0x194
V [libjvm.so+0x18babff] VMError::report_and_die(Thread*, void*, char const*, int, char const*, char const*, __va_list_tag*)+0x2f
V [libjvm.so+0xaff2e0] report_vm_error(char const*, int, char const*, char const*, ...)+0x100
V [libjvm.so+0x159fc02] PhaseIterGVN::init_verifyPhaseIterGVN()+0x152
V [libjvm.so+0x15a0e09] PhaseIterGVN::optimize()+0x19
V [libjvm.so+0x12e7e19] PhaseMacroExpand::expand_macro_nodes()+0xc79
V [libjvm.so+0xa28cbc] Compile::Optimize()+0xc6c
V [libjvm.so+0xa29ea7] Compile::Compile(ciEnv*, C2Compiler*, ciMethod*, int, bool, bool, bool, bool, DirectiveSet*)+0xf87
V [libjvm.so+0x82bbdb] C2Compiler::compile_method(ciEnv*, ciMethod*, int, DirectiveSet*)+0xfb
V [libjvm.so+0xa37b12] CompileBroker::invoke_compiler_on_method(CompileTask*)+0x392
V [libjvm.so+0xa38dc8] CompileBroker::compiler_thread_loop()+0x5b8
V [libjvm.so+0x17f768b] JavaThread::thread_main_inner()+0x20b
V [libjvm.so+0x17f30ea] Thread::call_run()+0x19a
V [libjvm.so+0x15027b6] thread_native_entry(Thread*)+0x106


With a product build we hit:

# SIGSEGV (0xb) at pc=0x00007f3f68aafb1f, pid=947075, tid=947091
#
# V [libjvm.so+0x70ab1f] PhaseCFG::do_DFS(Tarjan*, unsigned int)+0xdf

Current CompileTask:
C2: 567 1411 ! 4 SDD0::m3 (555 bytes)

Stack: [0x00007f3f2ca34000,0x00007f3f2cb35000], sp=0x00007f3f2cb30650, free space=1009k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0x70ab1f] PhaseCFG::do_DFS(Tarjan*, unsigned int)+0xdf
V [libjvm.so+0x70afe2] PhaseCFG::build_dominator_tree()+0x92
V [libjvm.so+0x7c78a1] PhaseCFG::do_global_code_motion()+0x11
V [libjvm.so+0x617267] Compile::Code_Gen()+0x467
V [libjvm.so+0x61bf06] Compile::Compile(ciEnv*, C2Compiler*, ciMethod*, int, bool, bool, bool, bool, DirectiveSet*)+0x17a6
V [libjvm.so+0x54313b] C2Compiler::compile_method(ciEnv*, ciMethod*, int, DirectiveSet*)+0x15b
V [libjvm.so+0x62480d] CompileBroker::invoke_compiler_on_method(CompileTask*)+0x3ad
V [libjvm.so+0x625988] CompileBroker::compiler_thread_loop()+0x428
V [libjvm.so+0xe0fb13] JavaThread::thread_main_inner()+0x133
V [libjvm.so+0xe0c59c] Thread::call_run()+0x13c
V [libjvm.so+0xbd1cc6] thread_native_entry(Thread*)+0xe6