pkg/52104: php-7.1.3 does not compile on Solaris 11

[joern.clausen%uni-bielefeld.de@localhost]

>Number:         52104
>Category:       pkg
>Synopsis:       php-7.1.3 does not compile on Solaris 11
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 23 08:25:00 +0000 2017
>Originator:     Joern Clausen
>Release:        
>Organization:
University of Bielefeld
>Environment:
>Description:
Compiling lang/php71 on Solaris 11.2/i86 using GCC 4.8.5 fails with

main/fastcgi.lo sapi/cgi/cgi_main.lo -lresolv -lrt -lm -lnsl -lsocket -lcrypto -lpthread -lgcc -lxml2 -lz -llzma -lrt -liconv -lm -lsocket -lnsl -lssl -lcrypto -lxml2 -lz -llzma -lrt -liconv -lm -lsocket -lnsl -lxml2 -lz -llzma -lrt -liconv -lm -lsocket -lnsl -lxml2 -lz -llzma -lrt -liconv -lm -lsocket -lnsl -lxml2 -lz -llzma -lrt -liconv -lm -lsocket -lnsl -lssl -lcrypto  -o sapi/cgi/php-cgi
UndefinedUndefined                              first           referenced
 symbol                 first     referenced 
  symbol in     file
isfinite                            ext/filter/logical_filters.o
ld: fatal: symbol referencing errors
                    in file
isfinite                            ext/filter/logical_filters.o
ld: fatal: symbol referencing errors
collect2: error: ld returned 1 exit status
collect2: error: ld returned 1 exit status
gmake: *** [sapi/cli/php] Error 1
gmake: *** Waiting for unfinished jobs....
gmake: *** [sapi/cgi/php-cgi] Error 1
Undefined                       first referenced
 symbol                             in file
isfinite                            ext/filter/logical_filters.o
ld: fatal: symbol referencing errors
collect2: error: ld returned 1 exit status
gmake: *** [sapi/phpdbg/phpdbg] Error 1
*** Error code 2


The prerequisites according to isfinite(3M) seem to be satisfied (math.h is probably included somewhere, -lm can be seen above).

The code in ext/filter hasn't changed since 7.1.2, which built on this machine. I can also find no other obvious changes in the pkgsrc code.
>How-To-Repeat:

>Fix: