RFR: Update build documentation to reflect compiler upgrades at Oracle

[Michal Vala]

Hi,

On 07/23/2018 07:13 PM, Erik Joelsson wrote:
> The build documentation needs to be updated to reflect the compiler updates that 
> took place at Oracle for JDK 11.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8208096
> 
> Webrev: http://cr.openjdk.java.net/~erikj/8208096/webrev.01/
> 
> /Erik
> 

OpenJDK is currently not buildable with Visual Studio <2015 due to missing 
`snprintf`[1].

We should either update the doc to minimal version 2015, or commit JDK-8208084 
from another RFR[2].

[1] - https://bugs.openjdk.java.net/browse/JDK-8208084
[2] - http://mail.openjdk.java.net/pipermail/build-dev/2018-July/022748.html
-- 
Michal Vala
OpenJDK QE
Red Hat Czech