RFR: JDK-8199405 Bump lowest supported gcc to 4.8

[Erik Joelsson]

I think this looks good. Hopefully nobody minds the version requirement 
bump.

/Erik


On 2018-03-09 03:29, Magnus Ihse Bursie wrote:
> If we bump the lowest supported version of gcc from 4.7 to 4.8, we can remove several checks in the configure script.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8199405
> WebRev: http://cr.openjdk.java.net/~ihse/JDK-8199405-bump-gcc-to-v4_8/webrev.01
>
> /Magnus