harfbuzz: check in harfbuzz-ng, add gyp define to use it

third_party/harfbuzz-ng/src/check-libstdc++.sh

+#!/bin/sh
+
+LC_ALL=C
+export LC_ALL
+
+if which ldd 2>/dev/null >/dev/null; then
+        :
+else
+        echo "check-libstdc++.sh: 'ldd' not found; skipping test"
+        exit 0
+fi
+
+test -z "$srcdir" && srcdir=.
+stat=0
+
+so=.libs/libharfbuzz.so
+if test -f "$so"; then
+        echo "Checking that we are not linking to libstdc++"
+        if ldd $so | grep 'libstdc[+][+]'; then
+                echo "Ouch, linked to libstdc++"
+                stat=1
+        fi
+else
+        echo "check-libstdc++.sh: libharfbuzz.so not found; skipping test"
+fi
+
+exit $stat