When oop map creation fails, we try to throw a LinkageError to propagate the error message. If this happens in the
compiler thread (for example, during OSR compilation), we fail because a compiler thread cannot initialize an exception
I've fixed this by bailing out with a meaningful message in case !Thread::can_call_java(). Please note that even if we
are able to instantiate an exception, we will still fail with ShouldNotReachHere because compute_map(TRAPS) is called
with CATCH (see comments in the bug for a detailed explanation). This fix is not about changing this behavior but to
fail with a meaningful error message during compilation. This should only happen if something is seriously broken (for
example, incorrect bytecode with -noverify, see TestLinkageErrorInGenerateOopMap). In this case we would probably hit
other issues as well if we would continue execution.