Remove deprecated_internalProblem.

pkg/front_end/lib/src/fasta/quote.dart

 // Copyright (c) 2016, 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.
 
 library fasta.quote;
 
-import 'deprecated_problems.dart'
-    show deprecated_inputError, deprecated_internalProblem;
+import 'deprecated_problems.dart' show deprecated_inputError;
+
+import 'problems.dart' show unhandled;
 
 import 'scanner/characters.dart'
     show
         $BACKSLASH,
         $BS,
         $CLOSE_CURLY_BRACKET,
         $CR,
         $FF,
         $LF,
         $OPEN_CURLY_BRACKET,
@@ skipping 24 matching lines @@
 
 Quote analyzeQuote(String first) {
   if (first.startsWith('"""')) return Quote.MultiLineDouble;
   if (first.startsWith('r"""')) return Quote.RawMultiLineDouble;
   if (first.startsWith("'''")) return Quote.MultiLineSingle;
   if (first.startsWith("r'''")) return Quote.RawMultiLineSingle;
   if (first.startsWith('"')) return Quote.Double;
   if (first.startsWith('r"')) return Quote.RawDouble;
   if (first.startsWith("'")) return Quote.Single;
   if (first.startsWith("r'")) return Quote.RawSingle;
-  return deprecated_internalProblem("Unexpected string literal: $first");
+  return unhandled(first, "analyzeQuote", -1, null);
 }
 
 // Note: based on [StringValidator.quotingFromString]
 // (pkg/compiler/lib/src/string_validator.dart).
 int lengthOfOptionalWhitespacePrefix(String first, int start) {
   List<int> codeUnits = first.codeUnits;
   for (int i = start; i < codeUnits.length; i++) {
     int code = codeUnits[i];
     if (code == $BACKSLASH) {
       i++;
@@ skipping 29 matching lines @@
       return lengthOfOptionalWhitespacePrefix(first, 3);
 
     case Quote.RawSingle:
     case Quote.RawDouble:
       return 2;
 
     case Quote.RawMultiLineSingle:
     case Quote.RawMultiLineDouble:
       return lengthOfOptionalWhitespacePrefix(first, 4);
   }
-  return deprecated_internalProblem("Unhandled string quote: $quote");
+  return unhandled("$quote", "firstQuoteLength", -1, null);
 }
 
 int lastQuoteLength(Quote quote) {
   switch (quote) {
     case Quote.Single:
     case Quote.Double:
     case Quote.RawSingle:
     case Quote.RawDouble:
       return 1;
 
     case Quote.MultiLineSingle:
     case Quote.MultiLineDouble:
     case Quote.RawMultiLineSingle:
     case Quote.RawMultiLineDouble:
       return 3;
   }
-  return deprecated_internalProblem("Unhandled string quote: $quote");
+  return unhandled("$quote", "lastQuoteLength", -1, null);
 }
 
 String unescapeFirstStringPart(String first, Quote quote) {
   return unescape(first.substring(firstQuoteLength(first, quote)), quote);
 }
 
 String unescapeLastStringPart(String last, Quote quote) {
   return unescape(
       last.substring(0, last.length - lastQuoteLength(quote)), quote);
 }
@@ skipping 23 matching lines @@
     case Quote.RawSingle:
     case Quote.RawDouble:
       return string;
 
     case Quote.RawMultiLineSingle:
     case Quote.RawMultiLineDouble:
       return !string.contains("\r")
           ? string
           : unescapeCodeUnits(string.codeUnits, true);
   }
-  return deprecated_internalProblem(
-      "Internal error: Unexpected quote: $quote.");
+  return unhandled("$quote", "unescape", -1, null);
 }
 
 const String incompleteSequence = "Incomplete escape sequence.";
 
 const String invalidCharacter = "Invalid character in escape sequence.";
 
 const String invalidCodePoint = "Invalid code point.";
 
 // Note: based on
 // [StringValidator.validateString](pkg/compiler/lib/src/string_validator.dart).
@@ skipping 71 matching lines @@
         }
       } else {
         // Nothing, escaped character is passed through;
       }
       if (code > 0x10FFFF) return error(i, invalidCodePoint);
     }
     result[resultOffset++] = code;
   }
   return new String.fromCharCodes(result, 0, resultOffset);
 }