PPC: Ensure predictable code size at map_check in LCodeGen::DoInstanceOfKnownGlobal.

test/mjsunit/mjsunit.status

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@@ skipping 588 matching lines @@
 
   # Deopt every n garbage collections collides with deopt every n times.
   'regress/regress-2653': [SKIP],
 }],  # 'deopt_fuzzer == True'
 
 ##############################################################################
 ['arch == ppc and simulator_run == True or arch == ppc64 and simulator_run == True', {
 
   # take too long with the simulator.
   'regress/regress-1132': [SKIP],
-
-  # these two issues started after uplevel, believe they share common cause
-  'debug-references': [SKIP],
-  'mirror-object': [SKIP],
 }],  # 'arch == ppc and simulator_run == True'
 ]