Fix knownfailures for test 152/154

Change jit exemption to jit & debug. Add missing bug numbers.
Fix typo from "tests" to "test".

Bug: 35917229
Bug: 35800768

Test: test/testrunner/testrunner.py  --host --jit -j32

Change-Id: I5f1039b4b2b6b533360824a5667075365e08d0fd
diff --git a/test/knownfailures.json b/test/knownfailures.json
index 50d70f1..535b94f 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -103,7 +103,8 @@
     {
         "test": "152-dead-large-object",
         "variant": "gcstress",
-        "description": ["152-dead-large-object requires a heap larger than what gcstress uses."]
+        "description": ["152-dead-large-object requires a heap larger than what gcstress uses."],
+        "bug": "http://b/35800768"
     },
     {
         "tests": ["908-gc-start-finish",
@@ -128,9 +129,10 @@
         "variant": "gcstress"
     },
     {
-        "tests": "154-gc-loop",
-        "variant": "gcstress | jit",
-        "description": ["154-gc-loop depends GC not happening too often"]
+        "test": "154-gc-loop",
+        "variant": "gcstress | jit & debug",
+        "description": ["154-gc-loop depends GC not happening too often"],
+        "bug": "http://b/35917229"
     },
     {
         "test": "115-native-bridge",