a few ignores for nvprmsaa4

TBR=
NOTRY=True
BUG=skia:

Review URL: https://codereview.chromium.org/850143003

expectations/gm/Test-Win8-ShuttleA-GTX660-x86-Debug/expected-results.json

@@ -18682,6 +18682,7 @@
           16258109186950173986
         ]
       ], 
+      "ignore-failure": true,
       "reviewed-by-human": true
     }, 
     "shadertext_pdf-poppler.png": {
@@ -21924,4 +21925,4 @@
       "reviewed-by-human": true
     }
   }
-}
+}

expectations/gm/Test-Win8-ShuttleA-GTX660-x86_64-Debug/expected-results.json

@@ -18684,6 +18684,7 @@
           16258109186950173986
         ]
       ], 
+      "ignore-failure": true,
       "reviewed-by-human": true
     }, 
     "shadertext_pdf-poppler.png": {
@@ -21924,4 +21925,4 @@
       "reviewed-by-human": true
     }
   }
-}
+}