Fix bug in equalsIgnoreAsciiCase.

lib/src/comparators.dart

Index: lib/src/comparators.dart
diff --git a/lib/src/comparators.dart b/lib/src/comparators.dart
index ca2b3c77772c73b1520b67d6ddd1dd7bce7007a5..b0824a82be5d992cc16e5af0420d9589a9ed48d1 100644
--- a/lib/src/comparators.dart
+++ b/lib/src/comparators.dart
@@ -34,8 +34,8 @@ bool equalsIgnoreAsciiCase(String a, String b) {
     if (aChar ^ bChar != _asciiCaseBit) return false;
     // If it's possible, then check if either character is actually an ASCII
     // letter.
-    int aCharUpperCase = aChar | _asciiCaseBit;
-    if (_upperCaseA <= aCharUpperCase && aCharUpperCase <= _upperCaseZ) {
+    int aCharLowerCase = aChar | _asciiCaseBit;
+    if (_lowerCaseA <= aCharLowerCase && aCharLowerCase <= _lowerCaseZ) {
       continue;
     }
     return false;