Compile stdc++ library with both static and dynamic linking.

libstdc++-v3/configure

Index: libstdc++-v3/configure
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index a4a4fae664660c2d5e1b22ac1392777e19f13faf..36767da725a50bd13e6e3ebc00977b90e338a56a 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -10170,7 +10170,7 @@ linux*oldld* | linux*aout* | linux*coff*)
   ;;
 
 # This must be Linux ELF.
-linux* | k*bsd*-gnu | kopensolaris*-gnu)
+nacl* | linux* | k*bsd*-gnu | kopensolaris*-gnu)
   version_type=linux
   need_lib_prefix=no
   need_version=no
@@ -10266,7 +10266,9 @@ fi
   # most powerpc-linux boxes support dynamic linking these days and
   # people can always --disable-shared, the test was removed, and we
   # assume the GNU/Linux dynamic linker is in use.
-  dynamic_linker='GNU/Linux ld.so'
+  if [ $host_os != 'nacl' ] ; then
+    dynamic_linker='GNU/Linux ld.so'
+  fi
   ;;
 
 netbsd*)
@@ -14096,7 +14098,7 @@ linux*oldld* | linux*aout* | linux*coff*)
   ;;
 
 # This must be Linux ELF.
-linux* | k*bsd*-gnu | kopensolaris*-gnu)
+nacl* | linux* | k*bsd*-gnu | kopensolaris*-gnu)
   version_type=linux
   need_lib_prefix=no
   need_version=no
@@ -14192,7 +14194,9 @@ fi
   # most powerpc-linux boxes support dynamic linking these days and
   # people can always --disable-shared, the test was removed, and we
   # assume the GNU/Linux dynamic linker is in use.
-  dynamic_linker='GNU/Linux ld.so'
+  if [ $host_os != 'nacl' ] ; then
+    dynamic_linker='GNU/Linux ld.so'
+  fi
   ;;
 
 netbsd*)