[turbofan] Speed up structural graph verification.

test/mjsunit/mjsunit.status

 # Copyright 2012 the V8 project authors. All rights reserved.
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 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
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 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
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@@ skipping 76 matching lines @@
   'debug-evaluate-locals': [PASS, NO_VARIANTS],
   'debug-evaluate-locals-capturing': [PASS, NO_VARIANTS],
   'debug-evaluate-locals-optimized': [PASS, NO_VARIANTS],
   'debug-evaluate-locals-optimized-double': [PASS, NO_VARIANTS],
   'debug-evaluate-recursive': [PASS, NO_VARIANTS],  # only in no-snap debug.
   'debug-liveedit-check-stack': [PASS, NO_VARIANTS],  # only in no-snap mode.
   'debug-liveedit-double-call': [PASS, NO_VARIANTS],
   'debug-set-variable-value': [PASS, NO_VARIANTS],
   'es6/debug-evaluate-blockscopes': [PASS, NO_VARIANTS],
 
-  # TODO(titzer): too slow in --turbo mode due to O(n^2) graph verification.
-  'regress/regress-1122': [PASS, NO_VARIANTS],
-
   # Assumptions about optimization need investigation in TurboFan.
   'regress-sync-optimized-lists': [PASS, NO_VARIANTS],
 
   # Fails in --turbo --always-opt mode.
   'regress/regress-105': [PASS, NO_VARIANTS],
 
   ##############################################################################
   # Too slow in debug mode with --stress-opt mode.
   'compiler/regress-stacktrace-methods': [PASS, ['mode == debug', SKIP]],
   'compiler/regress-funcaller': [PASS, ['mode == debug', SKIP]],
@@ skipping 721 matching lines @@
 ##############################################################################
 ['gcov_coverage', {
   # Tests taking too long.
   'array-functions-prototype-misc': [SKIP],
 
   # Stack overflow.
   'big-array-literal': [SKIP],
 }],  # 'gcov_coverage'
 
 ]