RFR(XS) 8133984) print_compressed_class_space() is only defined in 64-bit VM

[Vladimir Kozlov]

http://cr.openjdk.java.net/~kvn/8133984/webrev/

The call to Metaspace::print_compressed_class_space(st) in vmError.cpp 
is not guarded by #ifdef _LP64. So some C++ compilers complain.

I will push it into hs-comp.

Thanks,
Vladimir