nss: Add nativesdk to BBCLASSEXTEND and bugfix

Since shsignlibs is used
from the nss postinstall hook. It should be included in
nativesdk to make offline rootfs construction possible.

(From OE-Core rev: 42bc72d21226e76c9b013fc052f17d847dc6a97a)

Signed-off-by: David Nyström <david.nystrom@enea.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-support/nss/nss.inc

@@ -37,6 +37,10 @@ do_compile_prepend_class-native() {
     export NSPR_LIB_DIR=${STAGING_LIBDIR_NATIVE}
 }
 
+do_compile_prepend_class-nativesdk() {
+    export LDFLAGS=""
+}
+
 do_compile() {
     export CROSS_COMPILE=1
     export NATIVE_CC="gcc"
@@ -73,6 +77,11 @@ do_compile() {
         OS_TEST=${OS_TEST} \
 }
 
+
+do_install_prepend_class-nativesdk() {
+    export LDFLAGS=""
+}
+
 do_install() {
     export CROSS_COMPILE=1
     export NATIVE_CC="gcc"
@@ -193,4 +202,4 @@ FILES_${PN}-dbg = "\
     ${libdir}/.debug/* \
     "
 
-BBCLASSEXTEND = "native"
+BBCLASSEXTEND = "native nativesdk"