[8u] 8226392: Launcher should not enable legacy stdio streams on GNU/Linux (glibc)

[Florian Weimer]

* Severin Gehwolf:

> Could I please get reviews for this 8u only change? The JDK 8u build
> logic for launcher files includes linker version script files (a.k.a
> mapfiles). The script file for x86 (32bit) marks symbol _IO_stdin_used
> as local. When the symbol is not visible to the dynamic loader, glibc
> will use a legacy stdio implementation instead. This is a historic, x86
> (32bit) only glibc issue, I've been told.

It may impact other historic GNU/Linux targets, but I don't think they
have OpenJDK ports.  POWER and Z are 64-bit only, I assume.

Thanks,
Florian