Hydrogenized KeyedLoadGeneric stub: Fix string hash retrieval

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/363293002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22184 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Hydrogenized KeyedLoadGeneric stub: Fix BuildDecodeField

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/369673007

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22185 ce2b1a6d-e550-0410-aec6-3dcde31c8c00