icu-60.2 build failure 6.1-STABLE

[Mike Pumford <mpumford%mudcovered.org.uk@localhost>]

Getting the following building icu on a 6.1-STABLE system

c++ -I/usr/include -I/usr/pkg/include -D_REENTRANT  -DU_HAVE_ELF_H=1 
-DU_HAVE_NETBSD_ATOMIC_OPS=1 -DU_HAVE_ATOMIC=1 -DU_HAVE_STRTOD_L=0  -I. 
-I../common   -DU_ATTRIBUTE_DEPRECATED= -DU_I18N_IMPLEMENTATION -O2 
-march=i486 -I/usr/include -I/usr/pkg/include -W -Wall -pedantic 
-Wpointer-arith -Wwrite-strings -Wno-long-long -std=c++11    -c   -o 
number_decimfmtprops.ao number_decimfmtprops.cpp

number_decimalquantity.cpp: In member function 'void 
icu_60::number::impl::DecimalQuantity::_setToDoubleFast(double)':
number_decimalquantity.cpp:387:40: error: 'round' is not a member of 'std'
     auto result = static_cast<int64_t>(std::round(n));
                                        ^
number_decimalquantity.cpp:387:40: note: suggested alternative:
In file included from /usr/pkg/gcc48/include/c++/cmath:44:0,
                 from number_decimalquantity.cpp:9:
/usr/pkg/gcc48/lib/gcc/i486--netbsdelf/4.8.5/include-fixed/math.h:347:8: 
note:   'round'
 double round(double);
        ^
../config/mh-bsd-gcc:43: recipe for target 'number_decimalquantity.ao' 
failed
gmake[1]: *** [number_decimalquantity.ao] Error 1

No issue compiling the same pkgsrc tree on 8.0-BETA  or 7.1-STABLE.

Mike