Following crash observed in 'jdk-16+9-325 tier6-gc-zgc' CI testing.

#test - compiler/codecache/stress/UnexpectedDeoptimizationTest.java

(Run test open/test/hotspot/jtreg/:hotspot_compiler_all_gcs
 with macosx-x64-debug
 with -XX:+CreateCoredumpOnCrash -XX:+UseZGC
 #tier6-gc-zgc; id - id - jdk-16+9-325)

# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x0000000105515888, pid=75712, tid=31087
#
# JRE version: Java(TM) SE Runtime Environment (16.0+9) (fastdebug build 16-ea+9-325)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 16-ea+9-325, mixed mode, sharing, tiered, z gc, bsd-amd64)
# Problematic frame:
# V [libjvm.dylib+0x515888] Compile::can_alias(TypePtr const*, int)+0x38
......
--------------- T H R E A D ---------------

Current thread (0x00007fcd1f05cc20): JavaThread "C2 CompilerThread1" daemon [_thread_in_native, id=31087, stack(0x0000700012088000,0x0000700012188000)]


Current CompileTask:
C2: 762639 212505 4 compiler.codecache.stress.CodeCacheStressRunner::test (22 bytes)

Stack: [0x0000700012088000,0x0000700012188000], sp=0x00007000121837e0, free space=1005k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.dylib+0x515888] Compile::can_alias(TypePtr const*, int)+0x38
V [libjvm.dylib+0xbffc5f] PhaseIdealLoop::get_late_ctrl(Node*, Node*)+0x55f
V [libjvm.dylib+0xc00fc1] PhaseIdealLoop::build_loop_late_post_work(Node*, bool)+0x201
V [libjvm.dylib+0xbfba93] PhaseIdealLoop::build_loop_late(VectorSet&, Node_List&, Node_Stack&)+0x343
V [libjvm.dylib+0xbfa11e] PhaseIdealLoop::build_and_optimize(LoopOptsMode)+0x82e
V [libjvm.dylib+0x516d14] PhaseIdealLoop::optimize(PhaseIterGVN&, LoopOptsMode)+0xd4
V [libjvm.dylib+0x516e6d] Compile::optimize_loops(PhaseIterGVN&, LoopOptsMode)+0x9d
V [libjvm.dylib+0x511810] Compile::Optimize()+0x11b0
V [libjvm.dylib+0x50e8c3] Compile::Compile(ciEnv*, ciMethod*, int, bool, bool, bool, bool, DirectiveSet*)+0x12d3
V [libjvm.dylib+0x4060c0] C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x1d0
V [libjvm.dylib+0x52b0a8] CompileBroker::invoke_compiler_on_method(CompileTask*)+0x6c8
V [libjvm.dylib+0x52a6ec] CompileBroker::compiler_thread_loop()+0x34c
V [libjvm.dylib+0x1001170] JavaThread::thread_main_inner()+0x2a0
V [libjvm.dylib+0xffc4c7] Thread::call_run()+0x1b7
V [libjvm.dylib+0xdc1fdf] thread_native_entry(Thread*)+0x15f
C [libsystem_pthread.dylib+0x6109] _pthread_start+0x94
C [libsystem_pthread.dylib+0x1b8b] thread_start+0xf