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