dart2js: Exclude string interpolation tests from CRLF rewriting.

BUG=
TBR=johnniwinther@google.com

Review URL: https://codereview.chromium.org//1206953003.

.gitattributes

@@ -12,6 +12,8 @@
 
 # Windows files that should not be converted.
 tests/lib/mirrors/method_mirror_source_line_ending_crlf.dart -text
+tests/compiler/dart2js_extra/string_interpolation_test.dart -text
+tests/compiler/dart2js_extra/string_interpolation_dynamic_test.dart -text
 
 # Files to leave alone and not diff.
 *.png binary

tests/compiler/dart2js_extra/string_interpolation_dynamic_test.dart

@@ -60,7 +60,7 @@ void testMultiLine() {
   Expect.equals("\n", """${''}
 """);
   Expect.equals("\r", """${''}
-""");
+""");
   Expect.equals("\r\n", """${''}
 """);
   Expect.equals("\n", """${'\n'}""");

tests/compiler/dart2js_extra/string_interpolation_test.dart

@@ -56,7 +56,7 @@ void testMultiLine() {
   Expect.equals("\n", """${''}
 """);
   Expect.equals("\r", """${''}
-""");
+""");
   Expect.equals("\r\n", """${''}
 """);
   Expect.equals("\n", """${'\n'}""");