[oe] [meta-java] host gcc-9, icetea-7 gcc-9 but how older gcc versions?

[robert.berger.oe.devel]

Hi,

I tried to add support for a host gcc-9 and suggested this patch[1]

[1] 
https://github.com/RobertBerger/meta-java/commit/898a0ae33c9102387aae2e3427a007e3935e663e

and, as per your suggestion, since it restricts the host compiler to >= 
gcc9 I added "-Wno-unknown-warning".

https://github.com/RobertBerger/meta-java/commit/3d8ae5afb639ec7abcc48f15c74b42b373863c57

... but it does not build:

https://pastebin.com/B1nxHcPH

cc1plus: error: unrecognized command line option ‘-Wno-unknown-warning’ 
[-Werror]

That's my host gcc:

pokyuser at 3a469e7032d9:/workdir$ gcc --version
gcc (Ubuntu 9.2.1-17ubuntu1~16.04) 9.2.1 20191102
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

pokyuser at 3a469e7032d9:/workdir$

Please advise.

Regards,

Robert