2019Q4 gcc7 build failure on illumos

[Zhiwen Zheng <zhiwen%40701.xyz@localhost>]

cp /opt/pkgsrc/lang/gcc7/work/gcc-7.4.0/libstdc++-v3/config/abi/pre/gnu.ver libstdc++-symbols.ver.tmp
chmod +w libstdc++-symbols.ver.tmp
if test "x../../../../gcc-7.4.0/libstdc++-v3/config/abi/pre/float128.ver" != x; then \
  if grep '^# Appended to version file.' \
       ../../../../gcc-7.4.0/libstdc++-v3/config/abi/pre/float128.ver > /dev/null 2>&1; then \
    cat ../../../../gcc-7.4.0/libstdc++-v3/config/abi/pre/float128.ver >> libstdc++-symbols.ver.tmp; \
  else \
    sed -n '1,/DO NOT DELETE/p' libstdc++-symbols.ver.tmp > tmp.top; \
    sed -n '/DO NOT DELETE/,$p' libstdc++-symbols.ver.tmp > tmp.bottom; \
    cat tmp.top ../../../../gcc-7.4.0/libstdc++-v3/config/abi/pre/float128.ver tmp.bottom > libstdc++-symbols.ver.tmp; \
    rm tmp.top tmp.bottom; \
  fi; \
fi
/opt/pkgsrc/lang/gcc7/work/.tools/bin/grep -E -v '^[ 	]*#(#| |$)' libstdc++-symbols.ver.tmp | \
  /opt/pkgsrc/lang/gcc7/work/build/./gcc/xgcc -B/opt/pkgsrc/lang/gcc7/work/build/./gcc/ -B/opt/local/gcc7/i486-sun-solaris2.11/bin/ -B/opt/local/gcc7/i486-sun-solaris2.11/lib/ -isystem /opt/local/gcc7/i486-sun-solaris2.11/include -isystem /opt/local/gcc7/i486-sun-solaris2.11/sys-include    -E -P -include ../config.h - > libstdc++-symbols.ver || (rm -f libstdc++-symbols.ver ; exit 1)
rm -f libstdc++-symbols.ver.tmp
CXXFILT="/opt/local/bin/gc++filt"; export CXXFILT; \
perl /opt/pkgsrc/lang/gcc7/work/gcc-7.4.0/libstdc++-v3/../contrib/make_sunver.pl \
  libstdc++-symbols.ver \
  .libs/compatibility.o .libs/compatibility-debug_list.o .libs/compatibility-debug_list-2.o .libs/compatibility-c++0x.o .libs/compatibility-atomic-c++0x.o .libs/compatibility-thread-c++0x.o .libs/compatibility-chrono.o .libs/compatibility-condvar.o \
 `echo -lrt ../libsupc++/libsupc++convenience.la ../src/c++98/libc++98convenience.la ../src/c++11/libc++11convenience.la | \
    sed 's,/\([^/.]*\)\.la,/.libs/\1.a,g'` \
 > libstdc++-symbols.ver-sun || (rm -f libstdc++-symbols.ver-sun ; exit 1)
Unescaped left brace in regex is passed through in regex; marked by <-- HERE in m/^([ \t]*){ <-- HERE $/ at /opt/pkgsrc/lang/gcc7/work/gcc-7.4.0/libstdc++-v3/../contrib/make_sunver.pl line 216.
unhandled symbol:
There are 35 section headers, starting at offset 0x9dd0: at /opt/pkgsrc/lang/gcc7/work/gcc-7.4.0/libstdc++-v3/../contrib/make_sunver.pl line 141, <READELF> line 3.
gmake[6]: *** [Makefile:960: libstdc++-symbols.ver-sun] Error 1
gmake[6]: Leaving directory '/opt/pkgsrc/lang/gcc7/work/build/i486-sun-solaris2.11/libstdc++-v3/src'
gmake[5]: *** [Makefile:641: all-recursive] Error 1
gmake[5]: Leaving directory '/opt/pkgsrc/lang/gcc7/work/build/i486-sun-solaris2.11/libstdc++-v3/src'
gmake[4]: *** [Makefile:510: all-recursive] Error 1
gmake[4]: Leaving directory '/opt/pkgsrc/lang/gcc7/work/build/i486-sun-solaris2.11/libstdc++-v3'
gmake[3]: *** [Makefile:417: all] Error 2
gmake[3]: Leaving directory '/opt/pkgsrc/lang/gcc7/work/build/i486-sun-solaris2.11/libstdc++-v3'
gmake[2]: *** [Makefile:18409: all-stage1-target-libstdc++-v3] Error 2
gmake[2]: Leaving directory '/opt/pkgsrc/lang/gcc7/work/build'
gmake[1]: *** [Makefile:26382: stage1-bubble] Error 2
gmake[1]: Leaving directory '/opt/pkgsrc/lang/gcc7/work/build'
gmake: *** [Makefile:939: all] Error 2
*** Error code 2

Stop.
bmake[1]: stopped in /opt/pkgsrc/lang/gcc7
*** Error code 1

Stop.
bmake: stopped in /opt/pkgsrc/lang/gcc7

========================mk.conf===================
-bash-4.3# cat /opt/local/etc/mk.conf 
# Example /opt/local/etc/mk.conf file produced by bootstrap-pkgsrc
# Sun Mar  8 13:15:59 CST 2020

.ifdef BSD_PKG_MK	# begin pkgsrc settings

ABI=			32
PKGSRC_COMPILER=	gcc

PKG_DBDIR=		/opt/local/pkgdb
LOCALBASE=		/opt/local
VARBASE=		/opt/local/var
PKG_TOOLS_BIN=		/opt/local/sbin
PKGINFODIR=		info
PKGMANDIR=		man

TOOLS_PLATFORM.install?=	/opt/local/bin/bsdinstall
TOOLS_PLATFORM.awk?=		/opt/local/bin/nawk
TOOLS_PLATFORM.sed?=		/opt/local/bin/nbsed
TOOLS_PLATFORM.sh?=		/usr/bin/bash

.endif			# end pkgsrc settings
GCCBASE=/opt/tools
DISTDIR=/opt/distfiles

===============gcc in use is from joyent 2019Q4 tools repo=============
-bash-4.3# /opt/tools/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/opt/tools/gcc7/bin/gcc
COLLECT_LTO_WRAPPER=/opt/tools/gcc7/libexec/gcc/x86_64-sun-solaris2.11/7.4.0/lto-wrapper
Target: x86_64-sun-solaris2.11
Configured with: ../gcc-7.4.0/configure --disable-libstdcxx-pch --disable-nls --with-gxx-include-dir=/opt/tools/gcc7/include/c++/ --enable-libssp --enable-languages='c obj-c++ objc fortran c++' --enable-shared --enable-long-long --with-local-prefix=/opt/tools/gcc7 --enable-threads=posix --with-boot-ldflags='-static-libstdc++ -static-libgcc -Wl,-R/opt/tools/lib  ' --without-gnu-ld --with-ld=/usr/bin/ld --with-gnu-as --with-as=/opt/tools/bin/gas --prefix=/opt/tools/gcc7 --build=x86_64-sun-solaris2.11 --host=x86_64-sun-solaris2.11 --infodir=/opt/tools/gcc7/info --mandir=/opt/tools/gcc7/man --enable-option-checking=yes
Thread model: posix
gcc version 7.4.0 (GCC) 

================nescaped left brace in regex is passed through in regex; marked by <-- HERE in m/^([ \t]*){ <-- HERE $/ at /opt/pkgsrc/lang/gcc7/work/gcc-7.4.0/libstdc++-v3/../contrib/make_sunver.pl line 216. ========
    # Lines of the form '{'
    if (/^([ \t]*){$/) {    ############## I know nothing in perl, do this statement has syntax error?
        if ($in_extern) {
            print "$1##{\n";
        } else {
            print;
        }
        next;
    }