Quick compiler - fix run-test 019

Two problems:
  1.  Was treating an array object store as a regular array store
  2.  Codegen bug that (somewhat disturbingly) existed in the
      non-quick code.  I'm a little surprised that it hadn't
      shown up before now, but it would tend to be masked if
      the array base register in question was promoted.

Change-Id: I62bcb866174538ceedcc1309edcf22261237840a
diff --git a/src/compiler/codegen/GenCommon.cc b/src/compiler/codegen/GenCommon.cc
index 40c0f22..9082a49 100644
--- a/src/compiler/codegen/GenCommon.cc
+++ b/src/compiler/codegen/GenCommon.cc
@@ -1439,7 +1439,7 @@
   int regLen = INVALID_REG;
   if (needsRangeCheck) {
     regLen = rARG1;
-    loadWordDisp(cUnit, rlArray.lowReg, lenOffset, regLen);  // Get len
+    loadWordDisp(cUnit, rArray, lenOffset, regLen);  // Get len
   }
   /* rPtr -> array data */
   int rPtr = oatAllocTemp(cUnit);