Fix a couple of assert() statements that were failing with OOM error tests.

FossilOrigin-Name: 8eb3d7d8360530f364bbbebac53e1f0e6753d924
diff --git a/src/expr.c b/src/expr.c
index 094a454..9e3b664 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2360,7 +2360,7 @@
   }
   p->iReg = 0;
   pParse->nColCache--;
-  assert( cacheIsValid(pParse) );
+  assert( pParse->db->mallocFailed || cacheIsValid(pParse) );
 }
 
 
@@ -2405,7 +2405,7 @@
       p->tempReg = 0;
       p->lru = pParse->iCacheCnt++;
       pParse->nColCache++;
-      assert( cacheIsValid(pParse) );
+      assert( pParse->db->mallocFailed || cacheIsValid(pParse) );
       return;
     }
   }