RFR: JDK-8198724 Refactor FLAGS handling in configure

[Erik Joelsson]

On 2018-03-02 01:54, Magnus Ihse Bursie wrote:
>
> I actually don't know of any cases where CFLAGS ordering is relevant. 
> (LIBS is another issue) It's good to be aware of such issues, so 
> please enlighten me. :-)
If you have a flag that enables a feature and the corresponding 
disabling flag of the same, like -Wfoo -Wno-foo, then the latter 
overrides the former. Change the order and you get the opposite behavior.

-I directories are searched in order so if the same header name is found 
in multiple directories, you get differences.

/Erik