This is causing massive failures in our CI at higher tiers. Failures listed below.

Looks like JDK-8323727:
applications/ctw/modules/jdk_jshell.java
-XX:-TieredCompilation -XX:+StressReflectiveCode -XX:-ReduceInitialCardMarks -XX:-ReduceBulkZeroing -XX:-ReduceFieldZeroing

CompileCommand: exclude java/lang/invoke/MethodHandle.* bool exclude = true
CompileCommand: MemLimit *.* intx MemLimit = 0
int:1
  0  Root  === 0  [[ 0 1 3 57 61 63 66 67 70 73 77 ]] 
  3  Start  === 3 0  [[ 3 5 6 7 8 9 10 11 12 ]]  #{0:control, 1:abIO, 2:memory, 3:rawptr:BotPTR, 4:return_address, 5:jdk/internal/agent/Agent$StatusCollector:NotNull *, 6:int, 7:javax/management/remote/JMXServiceURL (java/io/Serializable) *}
 61  ConP  === 0  [[ 62 64 64 74 74 76 76 ]]  #precise jdk/internal/agent/Agent$StatusCollector: 0x00007f75a816a4e8:Constant:exact *  Klass:precise jdk/internal/agent/Agent$StatusCollector: 0x00007f75a816a4e8:Constant:exact *
 10  Parm  === 3  [[ 4 19 22 39 23 23 33 33 56 40 40 50 50 22 62 68 68 ]] Parm0: jdk/internal/agent/Agent$StatusCollector:NotNull *  Oop:jdk/internal/agent/Agent$StatusCollector:NotNull * !jvms: Agent$StatusCollector::addConnection @ bci:-1 (line 125)
 62  SubTypeCheck  === _ 10 61  [[ ]]  profiled at: jdk.internal.agent.Agent$StatusCollector::addConnection:11 !jvms: Agent$StatusCollector::addConnection @ bci:11 (line 127)

int:0
  0  Root  === 0  [[ 0 1 3 57 61 63 66 67 70 73 77 ]] 
 61  ConP  === 0  [[ 62 64 64 74 74 76 76 ]]  #precise jdk/internal/agent/Agent$StatusCollector: 0x00007f75a816a4e8:Constant:exact *  Klass:precise jdk/internal/agent/Agent$StatusCollector: 0x00007f75a816a4e8:Constant:exact *

==============================
  0  Root  === 0  [[ 0 1 3 57 61 63 66 67 70 73 77 ]] 


#  Internal Error (/workspace/open/src/hotspot/share/opto/subtypenode.cpp:113), pid=2302512, tid=2302530
#  assert(verify(phase)) failed: missing Value() optimization

Current CompileTask:
C2:12101 1478    b        jdk.jshell.DiagList::tally (98 bytes)

Stack: [0x00007f9eb72f4000,0x00007f9eb73f4000],  sp=0x00007f9eb73f0070,  free space=1008k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x1ae87e6]  SubTypeCheckNode::Ideal(PhaseGVN*, bool)+0x416  (subtypenode.cpp:113)
V  [libjvm.so+0x18867db]  PhaseGVN::transform(Node*)+0x6b  (phaseX.cpp:668)
V  [libjvm.so+0xff0c37]  GraphKit::gen_subtype_check(Node*, Node*)+0xe7  (graphKit.cpp:2903)
V  [libjvm.so+0xff114b]  GraphKit::subtype_check_receiver(Node*, ciKlass*, Node**)+0x5b  (graphKit.cpp:2949)
V  [libjvm.so+0x9d2681]  PredictedCallGenerator::generate(JVMState*)+0x171  (callGenerator.cpp:884)
V  [libjvm.so+0xd7f2ff]  Parse::do_call()+0x31f  (doCall.cpp:683)
V  [libjvm.so+0x1856a38]  Parse::do_one_bytecode()+0x478  (parse2.cpp:2723)
V  [libjvm.so+0x184351c]  Parse::do_one_block()+0x24c  (parse1.cpp:1593)
V  [libjvm.so+0x1844920]  Parse::do_all_blocks()+0x130  (parse1.cpp:724)
V  [libjvm.so+0x1847e93]  Parse::Parse(JVMState*, ciMethod*, float)+0xa93  (parse1.cpp:628)
V  [libjvm.so+0x9ce20b]  ParseGenerator::generate(JVMState*)+0x13b  (callGenerator.cpp:97)
V  [libjvm.so+0xbaf829]  Compile::Compile(ciEnv*, ciMethod*, int, Options, DirectiveSet*)+0x1899  (compile.cpp:805)
V  [libjvm.so+0x9cbab3]  C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x4a3  (c2compiler.cpp:147)
V  [libjvm.so+0xbbf4a0]  CompileBroker::invoke_compiler_on_method(CompileTask*)+0x780  (compileBroker.cpp:2345)
V  [libjvm.so+0xbc0d00]  CompileBroker::compiler_thread_loop()+0x530  (compileBroker.cpp:1989)
V  [libjvm.so+0x1120f8b]  JavaThread::thread_main_inner()+0x13b  (javaThread.cpp:776)
V  [libjvm.so+0x1b96676]  Thread::call_run()+0xb6  (thread.cpp:242)
V  [libjvm.so+0x17f4cf8]  thread_native_entry(Thread*)+0x118  (os_linux.cpp:877)


applications/ctw/modules/java_base_2.java
-XX:StressLongCountedLoop=2000000
OR
-ea -esa -XX:CompileThreshold=100 -XX:+UnlockExperimentalVMOptions -server -XX:+TieredCompilation -Djava.awt.headless=true
And some other flags combinations

# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (/workspace/open/src/hotspot/share/opto/vectornode.cpp:1148), pid=4137285, tid=4141381
#  assert(load_sz <= MaxVectorSize) failed: Unexpected load size

Current CompileTask:
C2:373898 106890    b  4       sun.text.CompactByteArray::compact (259 bytes)

Stack: [0x00007f49492f4000,0x00007f49493f4000],  sp=0x00007f49493eef60,  free space=1003k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x1c47d67]  LoadVectorMaskedNode::Ideal(PhaseGVN*, bool)+0x5d7  (vectornode.cpp:1148)
V  [libjvm.so+0x1886b2d]  PhaseIterGVN::transform_old(Node*)+0xbd  (phaseX.cpp:668)
V  [libjvm.so+0x188b355]  PhaseIterGVN::optimize()+0xc5  (phaseX.cpp:1054)
V  [libjvm.so+0x15ec765]  PhaseMacroExpand::expand_macro_nodes()+0x255  (macro.cpp:2686)
V  [libjvm.so+0xbaced2]  Compile::Optimize()+0xf02  (compile.cpp:2545)
V  [libjvm.so+0xbafe33]  Compile::Compile(ciEnv*, ciMethod*, int, Options, DirectiveSet*)+0x2023  (compile.cpp:860)
V  [libjvm.so+0x9cb933]  C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x4a3  (c2compiler.cpp:147)
V  [libjvm.so+0xbbf320]  CompileBroker::invoke_compiler_on_method(CompileTask*)+0x780  (compileBroker.cpp:2345)
V  [libjvm.so+0xbc0b80]  CompileBroker::compiler_thread_loop()+0x530  (compileBroker.cpp:1989)
V  [libjvm.so+0x1120e0b]  JavaThread::thread_main_inner()+0x13b  (javaThread.cpp:776)
V  [libjvm.so+0x1b96476]  Thread::call_run()+0xb6  (thread.cpp:242)
V  [libjvm.so+0x17f4af8]  thread_native_entry(Thread*)+0x118  (os_linux.cpp:877)

Many issues are already reported in JDK-8360557.

And many more ... TBD