Link against librt on solaris for semaphore and scheduler symbols

BUG=v8:3358
R=svenpanne@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/722673002

Cr-Commit-Position: refs/heads/master@{#25299}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25299 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

tools/gyp/v8.gyp

@@ -1427,7 +1427,7 @@
         ['OS=="solaris"', {
             'link_settings': {
               'libraries': [
-                '-lnsl',
+                '-lnsl -lrt',
             ]},
             'sources': [
               '../../src/base/platform/platform-solaris.cc',