Follow GHC change: No deprecated warnings for defining class methods

testsuite/tests/rename/should_compile/rn050.stderr

 
-rn050.hs:10:3: Warning:
-    In the use of `op' (imported from Rn050_A):
-    Deprecated: "Use bop instead"
-
 rn050.hs:13:7: Warning:
     In the use of `op' (imported from Rn050_A):
     Deprecated: "Use bop instead"

testsuite/tests/rename/should_compile/rn066.stderr

 
-rn066.hs:10:3: Warning:
-    In the use of `op' (imported from Rn066_A):
-    "Is that really a good idea?"
-
 rn066.hs:13:7: Warning:
     In the use of `op' (imported from Rn066_A):
     "Is that really a good idea?"