JDK 9 RFR of JDK-7130085 Port fdlibm hypot to Java

[Joseph D. Darcy]

Hello,

Please review the next portion of the port of fdlibm to Java:
    JDK-7130085 Port fdlibm hypot to Java
    http://cr.openjdk.java.net/~darcy/7130085.0/

As before with pow, this isn't necessarily the end state of the code 
we'd like to stop at, but it should be sufficiently idiomatic Java for 
an initial port.

To make comparison against the original C algorithm easier, I listed the 
C version of hypot as the base file to compare FdLibm.java against.

Thanks,

-Joe