Revert "Refactor codegen resource masks"

This reverts commit 07131ca93c301e5cbd6a8702d6af777e1662fe65

There's a problem with the x86 build - reverting until I track it down.

Change-Id: I938ed30617ee943c9dba2d52d034e6d198b32e4b
diff --git a/src/compiler/codegen/LocalOptimizations.cc b/src/compiler/codegen/LocalOptimizations.cc
index 356f4f9..c0e6036 100644
--- a/src/compiler/codegen/LocalOptimizations.cc
+++ b/src/compiler/codegen/LocalOptimizations.cc
@@ -121,7 +121,7 @@
        * region bits since stopMask is used to check data/control
        * dependencies.
        */
-        stopUseRegMask = (getPCUseDefEncoding() | thisLIR->useMask) & ~ENCODE_MEM;
+        stopUseRegMask = (ENCODE_REG_PC | thisLIR->useMask) & ~ENCODE_MEM;
     }
 
     for (checkLIR = NEXT_LIR(thisLIR);
@@ -298,7 +298,7 @@
        * conservatively here.
        */
       if (stopUseAllMask & ENCODE_HEAP_REF) {
-        stopUseAllMask |= getPCUseDefEncoding();
+        stopUseAllMask |= ENCODE_REG_PC;
       }
     }