Migrate test block 3 to Dart 2.0.

tests/corelib_strong/corelib_strong.status

Index: tests/corelib_strong/corelib_strong.status
diff --git a/tests/corelib_strong/corelib_strong.status b/tests/corelib_strong/corelib_strong.status
index 4973870a5464df5505b59f82d247809e7e63b8a8..e5a915ec52128285f4c701562677c0d082af388c 100644
--- a/tests/corelib_strong/corelib_strong.status
+++ b/tests/corelib_strong/corelib_strong.status
@@ -9,7 +9,6 @@
 # Skip tests that are not yet strong-mode clean.
 [ $strong ]
 big_integer_arith_vm_test: Skip
-bool_from_environment2_test: Skip
 core_runtime_types_test: Skip
 data_resource_test: Skip
 duration2_test: Skip
@@ -61,9 +60,6 @@ apply3_test: RuntimeError # Issue 29921
 big_integer_parsed_arith_vm_test: RuntimeError # Issue 29921
 big_integer_parsed_div_rem_vm_test: RuntimeError # Issue 29921
 big_integer_parsed_mul_div_vm_test: RuntimeError # Issue 29921
-bit_twiddling_bigint_test: RuntimeError # Issue 29921
-bool_from_environment_test: RuntimeError # Issue 29921
-compare_to2_test: RuntimeError # Issue 29921
 const_list_literal_test: RuntimeError # Issue 29921
 const_list_remove_range_test: RuntimeError # Issue 29921
 const_list_set_range_test: RuntimeError # Issue 29921