RFR: JDK-8199451 Create linux-aarch64 cross-compilation devkit, and fix cross-compilation

[Erik Joelsson]

I think this looks ok.

Just a note that the current devkit makefiles (at least used to) support 
creating a full Canadian cross set of tools and you have made some 
changes that disables this. For example changing $$host to $(TARGET) in 
the devkit.info file makes it so that one devkit can only have one 
target. This is probably fine because that is how we effectively use it 
today anyway.

/Erik

On 2018-03-12 03:08, Magnus Ihse Bursie wrote:
> While Oracle no longer actively supports linux-aarch64, it is good to 
> keep the build functioning for cross-compilation.
>
> I've created a devkit for cross-compilation from linux-x64 to 
> linux-aarch64, and fixed a recently introduced bug with buildjdk 
> SYSROOT_CFLAGS.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8199451
> WebRev: 
> http://cr.openjdk.java.net/~ihse/JDK-8199451-create-linux-aarch64-devkit/webrev.01
>
> /Magnus