fixes issue 484 + remove tls_taken check from drmgr_get_tls_field   and change to debug-only check in drmgr_set_tls_field
fixes issue 484
+ remove tls_taken check from drmgr_get_tls_field
  and change to debug-only check in drmgr_set_tls_field

git-svn-id: ed337ca7cdb08c0ba29d8fe58632bb7686892c2d@871 49cc7528-f6fd-11dd-9d1a-b59b2e1864b6

rnk/dynamorio,rnk/dynamorio,rnk/dynamorio,rnk/dynamorio,rnk/dynamorio