Disambiguate setters and getters when patching DDC SDK.

pkg/dev_compiler/tool/sdk_expected_errors.txt

Index: pkg/dev_compiler/tool/sdk_expected_errors.txt
diff --git a/pkg/dev_compiler/tool/sdk_expected_errors.txt b/pkg/dev_compiler/tool/sdk_expected_errors.txt
index 4d97ddb8bc4f10b2bfcb8fa34137e64a37a9a2a6..85e1f95fa6ef13f31aa2a603fb4b1e0b16dbaed6 100644
--- a/pkg/dev_compiler/tool/sdk_expected_errors.txt
+++ b/pkg/dev_compiler/tool/sdk_expected_errors.txt
@@ -2,9 +2,6 @@
 [error] A value of type 'Dimension' can't be assigned to a variable of type 'num'. (dart:html, line 40486, col 44)
 [error] The getter 'value' isn't defined for the class 'num'. (dart:html, line 40506, col 20)
 [error] A value of type 'Dimension' can't be assigned to a variable of type 'num'. (dart:html, line 40506, col 42)
-[error] Undefined name 'lineMode'. (dart:io/stdio.dart, line 57, col 10)
-[error] The name 'echoMode=' is already defined. (dart:io/stdio.dart, line 122, col 12)
-[error] The name 'lineMode=' is already defined. (dart:io/stdio.dart, line 143, col 12)
 [error] The getter 'packagesBase' isn't defined for the class 'IsolateNatives'. (dart:isolate, line 719, col 61)
 [error] Invalid override. The type of 'JsArray.[]=' ('(Object, E) → void') isn't a subtype of 'JsObject.[]=' ('(Object, dynamic) → dynamic'). (dart:js, line 370, col 3)
 [error] The argument type 'List' can't be assigned to the parameter type 'Iterable<Null>'. (dart:js_util, line 112, col 29)