VM build issue on MacOS after JDK-8267532

It was reported externally and I hit it myself on my Mac-x86 with old Xcode12.4 when building fastdebug VM with only open sources

src/hotspot/share/ci/ciMethodData.cpp:485:1: error: non-void function does not return a value in all control paths [-Werror,-Wreturn-type]
}
^
1 error generated.

JDK-8267532 added new method ciMethodData::exception_handler_bci_to_data() with ShouldNotReachHere() call on one exit withpout returning any value.