RFR(XS) : 8144695 : --disable-warnings-as-errors does not work for HotSpot build

[Igor Ignatyev]

as Mikael V correctly pointed out, there is missed $( ) in solaris/adlc.
here is the new webrev: http://cr.openjdk.java.net/~iignatyev/8144695/webrev.01/

and diff comparing to the prev. iteration:

> diff -r fe04b6ccb21a make/solaris/makefiles/adlc.make
> --- a/make/solaris/makefiles/adlc.make	Thu Dec 17 00:50:42 2015 +0300
> +++ b/make/solaris/makefiles/adlc.make	Thu Dec 17 01:47:39 2015 +0300
> @@ -77,7 +77,7 @@
>    WARNINGS_ARE_ERRORS ?= -w -xwe
>  endif
>  
> -CFLAGS_WARN = WARNINGS_ARE_ERRORS
> +CFLAGS_WARN = $(WARNINGS_ARE_ERRORS)
>  
>  # When using compiler version 5.13 (Solaris Studio 12.4), calls to explicitly
>  # instantiated template functions trigger this warning when +w is active.

— Igor

> On Dec 17, 2015, at 1:09 AM, Igor Ignatyev <igor.ignatyev at oracle.com> wrote:
> 
>> http://cr.openjdk.java.net/~iignatyev/8144695/webrev.00/
> 11 lines changed: 4 ins; 0 del; 7 mod; 
> 
> Hi,
> 
> could you please review the fix for 8144695[1]?
> 
> 8141543[1] propagated --disable-warnings-as-errors to hotspot build by setting WARNINGS_ARE_ERRORS to empty line. however in hotspot makefiles there are places where this variable is set explicitly.
> the fix changes = operator to ?= operator and updates adlc.make to use WARNINGS_ARE_ERRORS if it’s defined.
> 
> [1] https://bugs.openjdk.java.net/browse/JDK-8144695
> [2] https://bugs.openjdk.java.net/browse/JDK-8141543
> 
> Thanks,
> — Igor 
> 
>