RFR: 8152086: Remove SpaceMangler::mangle_region logging

[Thomas Schatzl]

Hi,

On Thu, 2016-03-17 at 10:14 +0100, Stefan Karlsson wrote:
> Hi all,
> 
> Please review this patch to remove the non-product mangling log
> output, 
> that shows up when we run with -Xlog:gc=trace.
> 
> http://cr.openjdk.java.net/~stefank/8152086/webrev.00/
> https://bugs.openjdk.java.net/browse/JDK-8152086
> 
> These lines only print a subset of all memory that we mangle. As a 
> separate RFE we might want to add a zap logging tag and annotate all 
> places where we zap/mangle memory.

  looks fine to me.

Thomas