[8u] RFR Backport 8238380: java.base/unix/native/libjava/childproc.c "multiple definition" link errors with GCC10

[Leslie Zhai]

Hi,

I would like to backport the fix for:

https://bugs.openjdk.java.net/browse/JDK-8238380

To OpenJDK 8 updates dev:

http://hg.openjdk.java.net/jdk8u/jdk8u-dev

The fix is mostly the same as the version that was committed in 15.

Webrev: http://cr.openjdk.java.net/~lzhai/8238380-8u/

Thanks,

Leslie Zhai