Fastdebug C2 crashes in StoreBNode::Ideal at least on linux-i586.

The related stack trace is
#0 0xffffe410 in __kernel_vsyscall ()
#1 0xb7de98f5 in raise () from /lib/libc.so.6
#2 0xb7deb1e1 in abort () from /lib/libc.so.6
#3 0x0695436b in os::abort ()
#4 0x06b0d139 in VMError::report_and_die ()
#5 0x0695ac9d in JVM_handle_linux_signal ()
#6 0x069565e0 in signalHandler ()
#7 <signal handler called>
#8 0x068f3b72 in StoreNode::Ideal_masked_input ()
#9 0x068f41cf in StoreBNode::Ideal ()
#10 0x069b00b6 in PhaseIterGVN::transform_old ()
#11 0x069af3d2 in PhaseIterGVN::optimize ()
#12 0x06569781 in Compile::Optimize ()
#13 0x0656549c in Compile::Compile ()
#14 0x064b3d63 in C2Compiler::compile_method ()
#15 0x065738df in CompileBroker::invoke_compiler_on_method ()
#16 0x06572d57 in CompileBroker::compiler_thread_loop ()
#17 0x06aafc8c in JavaThread::thread_main_inner ()
#18 0x06959548 in java_start ()
#19 0xb7f06192 in start_thread () from /lib/libpthread.so.0
#20 0xb7e8302e in clone () from /lib/libc.so.6