Fix crash in modPow (issue 23693); various bigint knowledge missing.

tests/corelib/corelib.status

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 [ $compiler == none && ($runtime == drt || $runtime == dartium || $runtime == ContentShellOnAndroid) ]
 bool_from_environment2_test: Skip
 bool_from_environment_test: Skip
 from_environment_const_type_test: Skip
 from_environment_const_type_undefined_test: Skip
 int_from_environment2_test: Skip
@@ skipping 188 matching lines @@
 # The regexp tests are not verified to work on non d8/vm platforms yet.
 regexp/*: Skip
 
 [ $runtime == vm ]
 regexp/global_test: Skip # Timeout. Issue 21709 and 21708
 
 [ $mode == debug ]
 regexp/pcre_test: Pass, Slow # Timeout. Issue 22008
 
 [ $mode == debug && $runtime == vm]
 big_integer_arith_vm_test/gcd: Pass, Crash # Issue 23693

[Ivan Posva, 2015/06/23 00:48:26]

Just confirming that gcd and modInv are not fixed by this CL, correct?

[srdjan, 2015/06/23 04:24:46]

Unfortunately, they are not fixed by that. It seems an issue in the range
analysis.

 big_integer_arith_vm_test/modInv: Pass, Crash # Issue 23693
 
-[ $runtime == vm ]
-big_integer_arith_vm_test/modPow: Pass, Crash # Issue 23693
-
 [ $runtime == vm && $arch == simarmv5te ]
 int_parse_radix_test/*: Pass, Slow
 big_integer_parsed_mul_div_vm_test: Pass, Slow
 
 [ $compiler == dart2js && $cps_ir ]
 apply2_test: RuntimeError # Please triage this failure.
 apply3_test: RuntimeError # Please triage this failure.
 apply4_test: RuntimeError # Please triage this failure.
 apply_test: RuntimeError # Please triage this failure.
 collection_from_test: RuntimeError # Please triage this failure.
@@ skipping 115 matching lines @@
 uri_file_test: Crash # Invalid argument(s)
 uri_http_test: Crash # Invalid argument(s)
 uri_ipv4_test: RuntimeError # Please triage this failure.
 uri_ipv6_test: Crash # Invalid argument(s)
 uri_normalize_path_test: RuntimeError # Please triage this failure.
 uri_parse_test: Crash # Invalid argument(s)
 uri_path_test: Crash # Invalid argument(s)
 uri_query_test: Crash # Internal Error: No default constructor available.
 uri_scheme_test: Crash # Invalid argument(s)
 uri_test: Crash # Invalid argument(s)