Crash under ProcessThrottler::setAssertionType():
Thread[0] EXC_BAD_ACCESS (SIGSEGV) (KERN_INVALID_ADDRESS at 0x0000000000000028)
[  0] 0x00000001b458201c WebKit`WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType) [inlined] std::__1::unique_ptr<WTF::Detail::CallableWrapperBase<void>, std::__1::default_delete<WTF::Detail::CallableWrapperBase<void> > >::reset(WTF::Detail::CallableWrapperBase<void>*) at memory:2620:28

     0x00000001b458200c:      add x16, x16, #0xb48     ; =0xb48 
     0x00000001b4582010:      add x16, x16, #0x10      ; =0x10 
     0x00000001b4582014:   pacdza x16
     0x00000001b4582018:      stp x16, x20, [x0]
 ->  0x00000001b458201c:      ldr x0, [x21, #0x28]
     0x00000001b4582020:      str x8, [x21, #0x28]
     0x00000001b4582024:      cbz x0, 0x2e1038         ; <+572> at ProcessThrottler.cpp:142:5
     0x00000001b4582028:      ldr x8, [x0]
     0x00000001b458202c:    ldraa x9, [x8, #0x8]!

[  0] 0x00000001b458201c WebKit`WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType) [inlined] std::__1::unique_ptr<WTF::Detail::CallableWrapperBase<void>, std::__1::default_delete<WTF::Detail::CallableWrapperBase<void> > >::operator=(std::__1::unique_ptr<WTF::Detail::CallableWrapperBase<void>, std::__1::default_delete<WTF::Detail::CallableWrapperBase<void> > >&&) at memory:2542
[  0] 0x00000001b458201c WebKit`WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType) [inlined] WTF::Function<void ()>::operator=(WTF::Function<void ()>&&) at Function.h:59
[  0] 0x00000001b458201c WebKit`WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType) [inlined] WebKit::ProcessAssertion::setInvalidationHandler(WTF::Function<void ()>&&) at ProcessAssertion.h:64
       60  	public:
       61  	    ProcessAssertion(ProcessID, const String& reason, ProcessAssertionType);
       62  	    virtual ~ProcessAssertion();
       63  	
    -> 64  	    void setInvalidationHandler(Function<void()>&& handler) { m_invalidationHandler = WTFMove(handler); }
       65  	
       66  	    ProcessAssertionType type() const { return m_assertionType; }
       67  	    ProcessID pid() const { return m_pid; }
       68  	
    
[  0] 0x00000001b458201c WebKit`WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType) + 544 at ProcessThrottler.cpp:139
       135 	        m_assertion = WTFMove(assertion);
       136 	    } else
       137 	        m_assertion = makeUnique<ProcessAssertion>(m_processIdentifier, assertionName(newType), newType);
       138 	
    -> 139 	    m_assertion->setInvalidationHandler([this] {
       140 	        assertionWasInvalidated();
       141 	    });
       142 	    m_process.didSetAssertionType(newType);
       143 	}
    
[  1] 0x00000001b4582003 WebKit`WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType) [inlined] WTF::Detail::CallableWrapperBase<void>::operator new(unsigned long) + 7 at Function.h:37:5
[  1] 0x00000001b4581ffc WebKit`WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType) [inlined] std::__1::__unique_if<WTF::Detail::CallableWrapper<WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType)::$_2, void> >::__unique_single std::__1::make_unique<WTF::Detail::CallableWrapper<WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType)::$_2, void>, WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType)::$_2>(WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType)::$_2&&) at memory:3033
[  1] 0x00000001b4581ffc WebKit`WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType) [inlined] decltype(auto) WTF::makeUnique<WTF::Detail::CallableWrapper<WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType)::$_2, void>, WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType)::$_2>(WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType)::$_2&&) at StdLibExtras.h:510
[  1] 0x00000001b4581ffc WebKit`WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType) [inlined] WTF::Function<void ()>::Function<WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType)::$_2, void>(WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType)::$_2&&) at Function.h:74
[  1] 0x00000001b4581ffc WebKit`WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType) [inlined] WTF::Function<void ()>::Function<WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType)::$_2, void>(WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType)::$_2&&) at Function.h:74
[  1] 0x00000001b4581ffc WebKit`WebKit::ProcessThrottler::setAssertionType(WebKit::ProcessAssertionType) + 512 at ProcessThrottler.cpp:139
[  2] 0x00000001b4587903 WebKit`WTF::Detail::CallableWrapper<WebKit::ProcessThrottler::sendPrepareToSuspendIPC(WebKit::IsSuspensionImminent)::$_3, void>::call() [inlined] WebKit::ProcessThrottler::processReadyToSuspend() + 131 at ProcessThrottler.cpp:198:9
[  2] 0x00000001b4587880 WebKit`WTF::Detail::CallableWrapper<WebKit::ProcessThrottler::sendPrepareToSuspendIPC(WebKit::IsSuspensionImminent)::$_3, void>::call() [inlined] WebKit::ProcessThrottler::sendPrepareToSuspendIPC(WebKit::IsSuspensionImminent)::$_3::operator()() + 44 at ProcessThrottler.cpp:219
[  2] 0x00000001b4587854 WebKit`WTF::Detail::CallableWrapper<WebKit::ProcessThrottler::sendPrepareToSuspendIPC(WebKit::IsSuspensionImminent)::$_3, void>::call() + 36 at Function.h:52